$39 Cheap United flights Chicago (ORD) to St. Louis (STL)

Scoring cheap one-way United Airlines flights from ORD to STL from $39 on Expedia is easy — just filter by “Price (lowest to highest).” Alternatively, check out our affordable return fares from $77 for your next getaway.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Search for return or one-way flights to St. Louis in January or February. You could find an affordable fare with United Airlines during these off-peak travel months.

To find cheap United Airlines fares from O’Hare Intl. Airport (ORD) to Lambert-St. Louis Intl. Airport (STL), start searching one to three months before your intended departure. Reserving domestic flights 34 to 86 days in advance could save you 25% compared to booking just 6 to 12 days ahead. The day you book can also affect the cost. Sunday is usually the most affordable, while Monday is often the most expensive for domestic flights. You can save 6% on average by choosing to book on a Sunday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC’s global airline sales database.

United Airlines has direct flights from O’Hare Intl. Airport (ORD) to Lambert-St. Louis Intl. Airport (STL), with 49 departures each week. Just choose the “Nonstop” and “Airline” filters while searching on Expedia to find all direct United Airlines flights to STL.

Leave O’Hare Intl. Airport (ORD) for Lambert-St. Louis Intl. Airport (STL) on a direct United Airlines flight, and you’ll be airborne for about 1h 32m.

Thursday has the most United Airlines flights from O’Hare Intl. Airport (ORD) to Lambert-St. Louis Intl. Airport (STL). With 7 daily departures, this is the best day of the week to find something that will work for your schedule.

The earliest flight from ORD to STL with United Airlines leaves at 9:15AM UTC-6. You’ll touch down at 10:54AM UTC-6. The last United Airlines flight of the day takes off at 8:15PM UTC-6 and arrives at 9:45PM UTC-6. With approximately 20% fewer cancellations for departures before midday, beginning your travel day early is typically the smartest option.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG’s global flight data platform.

United Airlines flights from O’Hare Intl. Airport (ORD) to St. Louis arrive at Lambert-St. Louis Intl. Airport (STL). This is the main gateway here.

With a rewarding loyalty program, United Airlines is a popular choice for many passengers flying from ORD to STL. Plus, if you’re a United Mileage Plus and One Key™ member booking through Expedia, you can earn OneKeyCash™* on eligible flights along with your airline miles.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.

United Airlines typically flies Canadair (Bombardier) Regional Jet 550 planes for flights from O’Hare Intl. Airport (ORD) to Lambert-St. Louis Intl. Airport (STL). This carrier also operates the Airbus A319 on this route. Remember that aircraft type can vary depending on operational reasons, so the plane you board might be different when you leave.

In most cases, you can cancel or change your flight, although there may be additional charges if you made your booking more than 24 hours ago. Need flexible options? Make use of Expedia’s “Changes included” or “No cancel fee” filter to find flights that won’t penalize you if you need to revise your plans. To make changes, visit “Trips,” select your flight and click on “Manage Booking” for more details.