About Chicago
Chicago is the most populous city in the U.S. state of Illinois and in the Midwestern United States. Located on the western shore of Lake Michigan, it is the third-most populous city in the United States, with a population of 2.74 million at the 2020 census. The Chicago metropolitan area has 9.41 million residents and is the third-largest metropolitan area in the country. Chicago is the seat of Cook County, the second-most populous county in the U.S. Source: "Chicago" by Wikipedia contributors (https://en.wikipedia.org/wiki/Chicago), licensed under CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/). Edit history on the linked Wikipedia page.
Overview
Chicago, United States is served by 2 airports tracked in this guide: Chicago O'Hare International Airport (ORD), Chicago Midway International Airport (MDW). Together they handle inbound and outbound flying for the metropolitan area, and each one links through to a full guide on this site with terminal, lounge, layover and ground-transport pages.
Choosing the right airport
Choosing between the airports in Chicago usually comes down to three things: which airline you are flying, which route you need, and how you plan to reach the airport from town. The primary international gateway carries most long-haul flights and partner-alliance connections. The secondary fields are usually friendlier for short domestic hops and low-cost carrier routes. Always confirm which airport your specific flight uses before you book a transfer. A wrong-airport pickup can cost an hour or more in cross-town traffic, and a few low-cost carriers in United States are notorious for using the secondary field even on routes you would expect at the main airport.
Ground transport
Ground transport between central Chicago and its airports normally includes licensed taxis with published rank fares, ride-hail apps with dedicated pickup points, public transport (bus, metro or rail) into the city centre, and rental car desks landside. For an early morning departure, a pre-booked airport transfer or an airport-hotel stay the night before is usually the most reliable option. Cash-only taxis still operate in parts of United States, so carrying a small amount of local currency is a sensible backup even if you plan to pay by card.
Layover tips
If you are visiting Chicago, it often makes sense to combine the airport visit with a short stay nearby. Look at hotel clusters within a 15-minute drive of arrivals if you have an overnight layover, and check luggage storage options at the airport if you want to head into the city centre between flights. Most major airports now have a left-luggage office airside or landside, although prices and hours vary widely.
When to fly through Chicago
When you fly through Chicago matters more than you might think. The morning bank between roughly 6am and 9am is the busiest at most airports, with a second peak in the late afternoon as long-haul flights time their arrivals into evening connection banks elsewhere. If your dates are flexible, a midday departure usually means shorter security lines and a calmer terminal. The shoulder seasons either side of the local holidays tend to be the cheapest and the least crowded.