Ready to find the ideal car for your Chicago adventure? Use the search form above to compare real-time rental rates across the city. Simply enter your desired pick-up location (Chicago O’Hare Airport [ORD], Midway [MDW], or any Chicago neighborhood), choose your dates, and hit “Search.” In seconds, you’ll see offers from dozens of trusted car rental companies in Chicago. Filter by vehicle type to get exactly what you need, maybe a compact car for zipping around downtown, a roomy SUV for a family trip to the suburbs, or a luxury car to travel in style. Booking is fast and flexible: reserve now and pay at pick-up with most suppliers and enjoy free cancellation up to 48 hours before pick-up if your plans change. With just a few clicks, you’ll lock in a great deal on a Chicago rental car, so you can save money and focus on enjoying the city.
Welcome to Chicago, the vibrant “Windy City” known for its stunning architecture, deep-dish pizza, and lakeside skyline. Exploring Chicago and its surrounding sights is easier and more rewarding with a rental car at your disposal. From downtown’s bustling Loop and Magnificent Mile to suburban gems and nearby Great Lakes shorelines, having your own set of wheels gives you the freedom to see it all. This page is your complete guide to securing a cheap car rental in Chicago. We’ve combined money-saving deals with local know-how so you can book with confidence. Whether you’re flying into O’Hare, arriving at Midway, or starting in the heart of the city, we’ll help you find the perfect ride quickly, easily, and affordably. Get ready to drive through Chicago’s diverse neighborhoods, cruise Lakeshore Drive, and embark on Illinois road trips, all on your schedule.
Note: “From” daily rates shown are recent examples for rentals in Chicago. Actual prices will vary by date and availability. Taxes and fees (around 15–20% in Illinois, including city-specific fees) are not included in the above base rates but will be calculated in your total before you confirm. Book early for peak periods (summer weekends, holidays) when demand is high, early birds snag the best deals! Also, renting from airport locations (like ORD or MDW) may include airport surcharges, while neighborhood locations may be slightly cheaper, we show you all options.
Driving in Chicago: Tips for Safe & Easy Navigation
Driving in Chicago offers the freedom to explore the city and its surroundings at your own pace. However, like any major metropolitan area, it has its quirks. Here are essential Chicago driving tips and local insights to help you navigate confidently:
Traffic & Rush Hours: Chicago is the third-largest city in the US, and traffic congestion is a part of life. Weekday rush hours typically peak 7:00–9:30 AM and 4:00–6:30 PM. The downtown area (the Loop) and major expressways such as I-90/94 (Kennedy and Dan Ryan Expressways), I-290 (Eisenhower), and I-55 (Stevenson) can become stop-and-go during these times. If you’re driving from O’Hare Airport into the city on I-90, for example, be prepared for heavy traffic especially during evening rush. Plan extra time or consider driving during off-peak hours (midday or later in the evening) to have a smoother trip. A GPS or map app is very helpful, not only for directions but also for real-time traffic routing. Chicago’s navigation apps may guide you along alternate routes (like using LSD, Lake Shore Drive or city surface streets) if the interstates are jammed. Always stay alert: Chicago drivers can be a bit aggressive but generally follow the rules; use your turn signals and keep a safe following distance in stop-and-go traffic.
Toll Roads (Illinois Tollways): Many highways around Chicago are toll roads, especially in the suburbs. Interstates like I-90 towards Rockford, I-294 Tri-State Tollway, I-88 (Reagan Tollway), and I-355 require toll payments. Illinois has fully cashless tolling, meaning there are no toll booths to pay cash. Tolls are collected via I-PASS or E-ZPass transponders or by photographing license plates. If your rental car has a toll transponder (or if the rental company offers a toll payment program), it can automatically pay your tolls (often for a small daily fee plus the toll costs). If not, don’t worry, you can still use the toll roads. The system will record your license plate, and you’ll have a limited time (about 14 days) to pay your tolls online via the Illinois Tollway website. Tip: Ask your rental provider about their toll policy. Sometimes using your own I-PASS (if you have one) or paying online can be cheaper than the rental company’s convenience fee. If you know you’ll be driving a lot on tollways (for example, heading out to the suburbs or on a road trip), consider these options to avoid surprise charges.
City Driving & Parking: Downtown Chicago’s streets are laid out in a grid, which makes navigation straightforward, but be mindful of one-way streets in the Loop. Traffic lights in the city are well-marked, and there are dedicated bike lanes in some areas, watch for cyclists especially in neighborhoods like Wicker Park or near the lakefront. Parking in Chicago ranges from plentiful to challenging depending on where you are. In downtown and popular districts (River North, Magnificent Mile, Wrigleyville), street parking is limited and often metered. Always read parking signs carefully, Chicago has street cleaning schedules and residential permit zones, which are strictly enforced. Meters in busy areas can cost ~$2–7 per hour (you can pay by credit card or phone app in most cases). For longer stays, it’s usually easier to use a parking garage or lot. Expect rates around $15–$20 for a few hours in downtown garages, and $30–$50 per day at downtown hotels or lots. If you’re planning to visit multiple sights, you might park once and use public transit or ride-shares to hop around the core, to avoid multiple parking fees. Pro tip: Some attractions offer parking validations or discounts (for example, certain museums or restaurants might validate garage parking). Also, consider using apps like SpotHero to find and reserve discounted parking spots in advance. Lastly, never leave valuables in plain sight inside your car, Chicago is generally safe, but an empty car (or at least one with items tucked away) is less tempting for break-ins anywhere.
Seasonal Considerations: Chicago’s weather changes with the seasons, and your driving strategies should too. Winter (Dec–Feb) brings snow, ice, and cold temperatures. The city and state do an excellent job plowing main roads, but after a heavy snowfall, side streets may stay snowy for a while. If you’re not used to winter driving, take it slow and increase your following distance, stopping on icy roads takes longer. Most rental cars in Chicago will come with all-season tires (sufficient for city driving), but if you plan trips to snowier regions or are visiting in deep winter, consider renting an AWD vehicle. Keep a scraper/brush in the car (many rentals provide this) to clear off snow. Before driving, clear all windows and mirrors of ice and snow for full visibility (it’s Illinois law). Also, watch for “black ice” on bridges and shaded roadways when temperatures dip below freezing. Summer (Jun–Aug) in Chicago is construction season, expect some detours or lane closures as the city repairs roads. Summer thunderstorms can be heavy; if rain is pounding, drive with headlights on and be cautious of pooled water. On the flip side, summer is a fantastic time to drive with windows down or enjoy the breeze along Lake Shore Drive, just be prepared for more pedestrians and cyclists out and about enjoying the weather too. Spring and fall are relatively mild, but fall leaves can make roads slippery when wet, and spring often brings rain, so adapt your driving accordingly.
Navigating the City & Neighborhoods: Chicago is a city of neighborhoods, and having a car makes it easier to explore places beyond the downtown loop. Use major arterials like North Ave, Western Ave, or Roosevelt Rd to traverse neighborhoods, but avoid driving through smaller residential streets at high speed, they often have speed humps and lots of stops. Chicago has some quirky intersections (like the six-corner intersections where three streets meet), just stay calm and follow the traffic lights and right-of-way rules. Right turn on red is allowed in Illinois (after a full stop), unless a sign says otherwise, this can help in clearing traffic at big junctions, but always yield to pedestrians crossing. If you’re headed to a Cubs game in Wrigleyville or a concert, anticipate heavy traffic and limited parking; you might park a bit away and walk or take the L (train) for the last stretch. Downtown tip: Lower Wacker Drive is an underground roadway that locals use to avoid surface traffic, it’s like a hidden highway under the city, but it can be confusing for newcomers and your GPS might cut out down there. Unless you’re confident, it’s okay to avoid Lower Wacker and stay above ground.
Fueling Up: Gas prices in the Chicago area tend to be around or slightly above the national average. As of mid-2025, expect roughly $3.50–$4.00 per gallon for regular unleaded. Prices are higher in the city than in the suburbs (taxes are a bit higher in Cook County and Chicago). If you need to refuel, you’ll find plenty of gas stations in the city, but downtown stations (like in River North or Streeterville) can be pricey. It can pay to drive a mile or two out of the tourist core or fill up in neighborhoods outside downtown for a better rate. When returning your rental, if you picked up at an airport, remember to refuel nearby to avoid the high refueling fees rental companies charge. For example, near O’Hare Airport, there are gas stations along Mannheim Road and Cumberland Ave just a few miles from the rental center, they are convenient for topping off. At Midway Airport, look along Cicero Avenue or 55th Street for fuel before drop-off. One more thing: Illinois gas pumps will ask for your ZIP code if paying by credit card, if you’re an international visitor without a US ZIP, you may need to pay inside the station.
By following these tips and staying alert, you’ll find that driving in Chicago is very manageable and opens up a world of opportunities beyond the beaten path. From spontaneous drives up the coast of Lake Michigan to discovering a new favorite pizza joint in the suburbs, a car gives you the keys to a true Chicago experience. Buckle up, enjoy the ride, and welcome to driving in the Windy City!
Road Trip Ideas from Chicago, IL
One of the best parts about renting a car in Chicago is the ability to embark on some fantastic road trips. The city’s central location means you can drive off in almost any direction and hit interesting destinations, from small Midwestern towns to other major cities and natural wonders. Here are three road trip itineraries from Chicago to spark your wanderlust:
1. Historic Route 66, Chicago to Santa Monica (Cross-Country Adventure)
Distance: ~2,400 miles one-way (plan 2 weeks or more for a comfortable, scenic trip).
Route: Begin at Chicago’s Route 66 Start Sign on Adams Street, the historic starting point of Route 66, known as “America’s Mother Road.” From Chicago, the old Route 66 path roughly follows I-55 through Illinois (passing Springfield), then I-44 through Missouri and Oklahoma, continuing on I-40 across Texas, New Mexico, and Arizona, and finally joins I-10 into California. You’ll wind your way through 8 states, ending at the Santa Monica Pier in Los Angeles, California, where Route 66 traditionally concludes at the Pacific Ocean.
Highlights: This is the ultimate American road trip, filled with nostalgia and quirky Americana. From Chicago, head south to see the Gateway Arch in St. Louis (a slight detour off the old route, but worth it for the iconic monument). Cruise through small towns in Illinois like Pontiac or Bloomington to see classic Route 66 museums and murals. In Missouri, stop in Springfield or at the Meramec Caverns (Jesse James’ hideout). Oklahoma offers the Blue Whale of Catoosa, a kitschy giant blue whale sculpture by a pond, a beloved Route 66 roadside attraction. In Texas, don’t miss Cadillac Ranch in Amarillo, where brightly painted cars are half-buried nose-down in a field (carry some spray paint to leave your mark!). New Mexico’s stretch includes Albuquerque’s neon signs and perhaps a detour to Santa Fe. Arizona will wow you with Petrified Forest National Park and Meteor Crater near Winslow, plus towns like Flagstaff and Kingman that still have that mid-century Route 66 vibe. Finally, in California, you’ll traverse the Mojave Desert, consider a stop at the ghost town of Calico, and then on to Los Angeles. Your finale: reaching Santa Monica Pier, where you can literally dip your toes in the Pacific after an epic journey. Take a photo with the “End of the Trail, Route 66” sign on the pier!
Tips: Much of historic Route 66 has been replaced by modern interstates, but you can often drive on the signposted historic segments of the old road, which parallel the highway for a more scenic and nostalgic experience. Allow extra time to explore small towns, half the fun is dining at vintage diners and staying at retro motels with neon signs. Summers can be extremely hot in stretches of the Southwest (100°F+ in Arizona and California), so ensure your car’s AC is working well and carry plenty of water. Thunderstorms can pop up in the Midwest during summer, be prepared to slow down in heavy rain. Unlimited mileage rentals make this long journey feasible, and one-way rentals from Chicago to Los Angeles are possible (we often have specials to waive the one-way drop fee on popular cross-country routes, check with us when booking). Lastly, embrace the spirit of Route 66: it’s not about getting there fast on the interstate; it’s about the journey. So take the scenic detours, snap photos of funny roadside attractions, and enjoy every mile of Americana on this classic road trip.
2. Great Lakes Circle Tour, Lake Michigan Loop
Distance: ~1,100 miles round-trip loop (suggest 5–7 days to fully enjoy).
Route: This scenic loop road trip circles Lake Michigan, one of the Great Lakes. Start in Chicago and head north into Wisconsin via I-94. You’ll follow the lake’s western shore through Milwaukee and Green Bay. From the top of Wisconsin, cross into Michigan’s Upper Peninsula (UP) over the Menominee area or via Marinette, WI. Continue east in the UP and then south over the Mackinac Bridge (a highlight itself!) into Michigan’s Lower Peninsula. Drive down Michigan’s west coast along routes like US-31, passing through beach towns, all the way to Indiana and back to Chicago.
Highlights: This trip is all about lakefront beauty, charming small towns, and diverse regional culture. First stop, Milwaukee, WI (about 1.5 hours from Chicago): enjoy a brewery tour or the Harley-Davidson Museum in this city on the lake. Continuing north, Green Bay offers Lambeau Field for football fans and picturesque Door County peninsula not far away (if time permits, Door County’s quaint villages and cherry orchards are a worthwhile side trip). Crossing into Michigan’s Upper Peninsula, you’ll find more rugged natural beauty, consider a detour to Pictured Rocks National Lakeshore on Lake Superior’s shore (spectacular colored cliffs and rock formations, about 2 hours one-way from the Mackinac Bridge but unforgettable). Back on our main loop, crossing the Mackinac Bridge is a thrill, it’s one of the longest suspension bridges in the world, connecting to Mackinaw City. You can take a ferry to Mackinac Island (no cars allowed there, a nice respite to walk or bike around and try some famous fudge). Continue down along Lake Michigan’s eastern shore: don’t miss Sleeping Bear Dunes National Lakeshore near Traverse City, MI, towering sand dunes with incredible views of the lake (you can even climb them or drive the Pierce Stocking Scenic Drive). Traverse City itself is great for wineries and has a lovely small-town vibe. Further south, stop in Grand Haven or Holland, MI, known for beautiful beaches (yes, Michigan has great beaches!) and in Holland’s case, a Dutch heritage with windmills and tulips in spring. As you loop back toward Chicago, you might pass through Indiana Dunes National Park, where sandy dunes meet the lake right before you return to the urban skyline.
Tips: This loop crosses three states, so keep some coins or small bills handy for a few toll roads (the Chicago area and some Michigan toll bridges). Weather can vary by region: summers are delightful for swimming in Lake Michigan (water is warmer by late July), while fall offers stunning foliage especially in Wisconsin and Michigan. Winter driving in the northern sections can be challenging due to lake-effect snow, if attempting in winter, ensure you have a suitable vehicle and check road conditions frequently. Many beach towns are seasonal, bustling in summer, quieter in winter. Plan for extra driving time on scenic coastal roads, which are slower than interstates but far more rewarding. Finally, bring a cooler, you’ll find farmers’ markets, cheese shops in Wisconsin, and fruit stands in Michigan (cherries, apples, etc.) perfect for road trip snacks. This Great Lakes road trip will show you a quieter, nature-rich side of the Midwest far from Chicago’s big-city bustle.
3. Blues & BBQ Road Trip, Chicago to New Orleans (The Heart of America’s Music Highway)
Distance: ~950 miles one-way (driveable in 2 long days, but 5–7 days recommended to enjoy stops).
Route: Head south from Chicago on I-57 to start this musical journey. You’ll travel through Illinois into Missouri, then down through the length of Arkansas and Mississippi on I-55, eventually reaching Louisiana. Major waypoints include St. Louis, Memphis, and Jackson before the final leg to New Orleans. (Alternatively, swing through Nashville by taking I-57 to I-24, then join I-55 via Memphis, a bit longer, but adds country music flavor to the trip.)
Highlights: This drive takes you through the cradle of American blues, jazz, and rock ‘n’ roll. First stop suggestion: St. Louis, MO (about 5 hours from Chicago via I-55). In St. Louis, see the Gateway Arch on the Mississippi River and perhaps visit Blues clubs on Broadway or grab some famous St. Louis barbecue ribs. Continuing south, you’ll reach Memphis, TN, roughly another 4 hours down I-55. Memphis is a must: tour Graceland, home of Elvis Presley, to delve into rock history, and visit Beale Street for live blues music and lip-smacking Memphis BBQ. The National Civil Rights Museum at the Lorraine Motel offers deep historical context and is well worth a stop. As you go further south, you’re now in Mississippi Delta blues country, consider detouring on Route 61 (the “Blues Highway”) through Clarksdale, MS. In Clarksdale, the famed Crossroads (Highway 61 & 49) legend of Robert Johnson awaits, and you can visit the Delta Blues Museum or catch live blues at Ground Zero Blues Club. Back on I-55, pass through Jackson, MS (the state capital) and then prepare for Louisiana. New Orleans is about 3 hours from Jackson. Arrive in New Orleans, LA, where jazz fills the air in the French Quarter and Creole cuisine rewards your long drive. Stroll down Bourbon Street, enjoy a jazz brunch, and reflect on the rich tapestry of music and culture you’ve experienced along the way.
Tips:One-way rental from Chicago to New Orleans is very feasible, many travelers do this to escape winter cold; check with us for any one-way fee (sometimes specials make it free or minimal). The best time for this trip might be spring or fall, you avoid Chicago’s winter snow and the Deep South’s peak summer heat. If traveling in summer, be prepared for hot, humid weather especially in Mississippi and Louisiana (make sure your car’s AC is in top shape). When driving through rural stretches of Arkansas and Mississippi, keep your gas tank above half, services can be 30-40 miles apart in some areas. Also, the speed limits in these rural interstates can be 70 mph, but watch for sudden slowdowns near towns or construction zones. Culturally, this is a diverse trip: you’ll pass roadside stands selling sweet tea and pecans, hear gospel or country on the radio, and see the landscape change from Midwestern plains to Southern bayous. Embrace it! Grab some Chicago snacks for the road and trade them for beignets and café au lait in New Orleans at the end. This journey is as much about the people and places as the miles, roll down your windows and enjoy the sounds of America on this road trip.
Frequently Asked Questions
Generally, yes, rentals in Chicago (and everywhere) are typically provided with a full tank of gas, and you’re expected to return the car with a full tank to avoid extra charges. If you don’t, the rental company will refuel it for you, but at a much higher price per gallon (often double the pump price, plus a service fee). We strongly recommend finding a gas station near your drop-off location and topping off. As mentioned, near Chicago’s airports there are convenient gas stations a few miles away (just keep your receipt in case they question it). Some companies offer a prepaid fuel option: you pay for a full tank up front at a competitive rate and you can bring the car back empty. This can be convenient if you know you’ll be very tight on time or don’t want the hassle of refueling right before drop-off, but note, there’s no refund for unused fuel, so it benefits you only if you’ll truly use most of the tank. Otherwise, it’s more cost-effective to fill up yourself. Quick tip for returns: after refueling, drive the car a few minutes to reach the return site, the fuel gauge should still read “Full”. If it’s just a hair below full, the agent might charge you a tiny amount for fuel; better to top off completely. In summary: either prepay for convenience or fill it up on your own to avoid extra fees.
Almost all rental cars in Chicago (and the U.S. in general) are automatic transmission. In fact, you’d be hard-pressed to even find a manual (“stick shift”) rental car here. The vast majority of American drivers use automatic cars, and rental fleets reflect that. So unless you specifically seek out a specialty car from a niche rental company, assume your car will be an automatic. This is good news if you’re not used to manual, you can focus on navigating without worrying about shifting gears in city traffic. For international visitors who prefer manual, sorry, it’s just not a common offering in the States, especially not in standard categories. On the bright side, automatics make it easier to handle Chicago’s stop-and-go traffic and you won’t stall on those occasional hilly streets. So, rest assured, you can confidently book any car type and expect an automatic transmission by default.
In Illinois (and generally across the U.S.), if your home country driver’s license is in English (or uses the Roman alphabet), you do not need an International Driving Permit. Your valid foreign driver’s license will be accepted by the rental company and is legally sufficient to drive. For example, licenses from Canada, the UK, the EU, Australia, etc. are all in English and easily understood. If your license is in a non-Latin script (e.g., in Chinese, Arabic, Cyrillic, etc.), it’s highly recommended to carry an IDP, which is basically an official translation of your license into multiple languages including English. An IDP is only a translation and must be carried alongside your original license, it’s not valid alone. Some rental counters might ask for an IDP if they have difficulty reading your native license. Also note: you must have your passport as well when renting (foreign renters need to show a passport for ID). The IDP is easy to obtain in your home country before travel (usually through an automobile association). So in summary: Not required if your license is already in English, but necessary as a translation if it isn’t. And regardless, you must present a valid, physical driver’s license (digital copies not accepted) to rent a car.
Most major Chicago attractions have parking available, the question is cost and sometimes availability. Navy Pier: has its own parking garages, but they can fill up on busy summer weekends. Expect to pay around $30 for a day. Arriving early in the day often guarantees a spot. Millennium Park/The Art Institute: there are large underground garages in Grant Park and Millennium Park. Plenty of space, but not cheap (around $25+ for a few hours). Museums (Field Museum, Shedd Aquarium, Adler Planetarium): These are clustered on Museum Campus. There’s a big paid parking lot by the Field Museum and Adler or the Soldier Field garage; on a normal day you’ll find parking ($25 or so). On days when there’s a big event (like a Bears game at Soldier Field), parking is tougher, check schedules. Lincoln Park Zoo: has a dedicated lot; pretty reasonable rates by Chicago standards and usually spots available except maybe peak weekend afternoons. Wrigley Field (Cubs) and United Center (Bulls/Blackhawks): these have limited official parking (especially Wrigley, in a dense neighborhood). It’s common to reserve spots in advance or use private lots. For Wrigley Field, many people park remotely and take the L train in on game days. Shopping on Magnificent Mile: use one of the many public garages off Michigan Ave, they often have discounted evening or weekend rates, and stores might validate. Overall tip: Chicago has a useful app/website (Chicago Parking Map or SpotHero/Parkwhiz) where you can find and even reserve parking at a discount. If you know where you’re going, a little prep can save time and money. And don’t forget about metered street parking, if you find a spot on the street near your destination, check the meter (many areas allow 2-3 hours max). Rates vary by neighborhood, roughly $2-7/hour as mentioned. Pay at the pay box or via app, and you’re good. Just watch the clock; Chicago parking enforcement is quite efficient with tickets if meters expire or if you’re in a tow zone during rush hour!
Yes, the Chicago area has toll roads (Illinois Tollway) mainly in the suburbs. If you’re driving on interstates that encircle or leave the city (like I-90 towards Wisconsin, I-88 west, I-355, I-294, I-57/I-94 heading to Indiana), you’ll likely encounter tolls. As mentioned above, Illinois uses cashless tolling, so you’ll either need a toll transponder (I-PASS/E-ZPass) or pay online for any tolls you incur. Within the city of Chicago itself, there are no tolls on city streets or downtown expressways (the Kennedy, Dan Ryan, Eisenhower, and Stevenson within the city are free). One exception: if you use the Chicago Skyway (I-90), a toll bridge on the south side that connects to Indiana, there is a toll (around $5) for that. There are no congestion charges or urban driving fees like some international cities have. Just normal tolls on certain highways. We recommend planning your route and seeing if it involves toll roads. If you prefer to avoid tolls, you often can take alternative routes (for example, instead of the tollway to Milwaukee, you could take the older highway US-41). But toll roads are faster. The toll costs themselves are usually a few dollars each. When renting, ask about a toll pass option, most companies will offer a daily rate for a transponder that covers all tolls (convenient but usually around $10/day plus tolls). If you decline it, you can still drive toll roads and just pay after, but you must remember to do so online. Also note: if you drive into neighboring Indiana, that state also has some tolls (like the Indiana Toll Road heading toward Ohio), those can also be paid online or via the same transponder if you have one.
That depends on your plans, but here are some guidelines: If you’re mostly sticking to downtown and solo or with one companion, a compact or midsize car is ideal, easy to drive and park on city streets and more fuel-efficient for urban traffic. Parking spaces in older parts of Chicago can be snug, so a smaller car can reduce parking stress. For families or groups of 4-5 with luggage, a standard/full-size sedan or small SUV provides more comfort and cargo space, great for city and highway driving alike. Visiting in winter or planning side trips to places like Wisconsin or Michigan in snowy months? Consider an SUV with all-wheel drive for better traction (roads are plowed in Chicago, but AWD can help on slush or if you venture to ski areas). If your itinerary involves long drives or you simply love comfort, a full-size SUV or minivan might be worth it for extra space, especially if you have kids and gear. Chicago also has some luxury and convertible rentals available: a luxury car could be fun for a business trip or a special occasion, and while a convertible isn’t practical in winter, in summer it’s a joy to drive by the lakefront with the top down. Lastly, consider fuel economy, gas prices aren’t extreme here, but if you plan a lot of driving, a car with good MPG (or even a hybrid) will save you a few bucks. In summary, match the vehicle to your group size and season, and you’ll be set.
If you plan to stay within downtown Chicago and visit only central attractions, you might manage with public transit (the CTA trains/buses, aka the “L”) and rideshare/taxis. Chicago’s public transportation is decent in the city proper: you can take the train from O’Hare into downtown, and there are L lines and buses covering many tourist spots. However, Chicago is a sprawling metro area and many worthwhile destinations (even within the city limits, like the Museum of Science & Industry, or neighborhoods like Pilsen or Oak Park) are much easier to reach by car. Parking and traffic in downtown can be a hassle, but outside of the core, having a car is often the quickest way to get around. If your plans include venturing beyond downtown, say to suburban sites, doing a day trip to Milwaukee or Starved Rock State Park, or if you simply value the freedom to go anywhere anytime, then renting a car is definitely worth it. Also, if you’re traveling with family or a group, a car often ends up cheaper and more convenient than multiple rideshares/trains, especially when factoring in time and flexibility. Many visitors choose a hybrid approach: use a rental car for part of their trip (for road trips and exploring), and maybe not for the couple days they’re just in the dense city center. Ultimately, if you want to explore Chicagoland and beyond on your own schedule, a rental car is the way to go.