$163 Cheap United flights Miami (MIA) to St. Louis (STL)

Finding cheap one-way United Airlines flights from MIA to STL from $163 on Expedia is easy — just filter by “Price (lowest to highest).” Or check out our affordable return fares from $302 for your next adventure.**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 months.

To find cheap United Airlines fares from Miami Intl. Airport (MIA) to Lambert-St. Louis Intl. Airport (STL), start searching one to three months before your planned departure. Securing 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 influence the price you pay. Sunday is typically the cheapest, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking 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.

Click on the “Nonstop” filter when looking for direct United Airlines flights from MIA to STL. You’ll also be able to compare other carriers offering the same nonstop trip.

Find United Airlines’s earliest flights from MIA to STL by selecting the “Morning” and “Early Morning” filters. Not only will you arrive sooner, early departures also experience 20% fewer cancellations.**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.

Lambert-St. Louis Intl. Airport (STL) is the primary St. Louis gateway for United Airlines flights from Miami Intl. Airport (MIA).

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

You can usually cancel or reschedule your flight, although there may be additional charges if your booking was made over 24 hours ago. Need flexible options? Make use of our “No cancel fee” and “Changes included” filters to find flights that won’t charge extra if you have to alter your plans. To make modifications, go to “Trips,” select your flight and click on “Manage Booking” for more details.