$139 Cheap United flights from Boston to St. Louis (BOS to STL)

Find The Best Day To Fly from Boston to St. Louis

Amazing United BOS to STL Flight Deals

The cheapest flights to Lambert-St. Louis Intl. found within the past 7 days were $254 round trip and $139 one way. Prices and availability subject to change. Additional terms may apply.

Frequently asked questions

Can I catch a flight from Logan Intl. Airport (BOS) to Lambert-St. Louis Intl. Airport (STL) right now?
Make sure you visit our Covid-19 Travel Advisor to see if there are any present travel advice reports and quarantine requirements in place in Lambert-St. Louis Intl. Airport (STL) when jet-setting from BOS.
What terminal is United Airlines at Logan Intl. Airport (BOS)?
Once you receive the boarding pass for your United Airlines flight from Logan Intl. Airport to Lambert-St. Louis Intl. Airport (STL), you should be able to determine which terminals you’ll be jetting in and out of. Your carrier will be able to help if those details are missing from your ticket.
Are there United Airlines non-stop flights from BOS to STL?
If you want to travel with United Airlines from Logan Intl. Airport to Lambert-St. Louis Intl. Airport (STL), you’ll have to make at least one stopover. While you’re waiting for your connection, take the chance to grab a bite to eat or stretch your legs.
How long is a United Airlines flight from BOS to STL?
Enjoy some in-flight shut-eye and begin your getaway feeling refreshed and relaxed. You’ll have sufficient time to do so when traveling with United Airlines between BOS and STL, with the flight taking an average of 4 hours and 22 minutes.
How many direct and indirect flights does United Airlines fly from BOS to STL?
When journeying from BOS to STL, you’ll discover around 6 United Airlines daily flights to choose from.
If I am not able to travel due to COVID-19, can I change my booking to a later date?
For more info about changing your flight to Lambert-St. Louis Intl. Airport (STL), please visit our Customer Service Portal.
What is the best day to buy a plane ticket?
This just in! Airfares offered on Thursdays tend to be the cheapest, according to flight demand on Travelocity in 2021. Tuesday and Wednesday prices are also good, but you may want to prepare your budget if booking during the weekend, as data shows that is when prices are generally at their highest.
What are the cheapest days to fly?
Frequent travelers may already know this, but earlier in the week can be the cheapest time to fly. In 2021, flights departing on a Monday were generally the cheapest of the week, whereas you may pay a premium for weekend flights when demand is usually high. On average, tickets were most expensive for Saturday departures, so if you need to fly out on a weekend, you might look for deals ahead of time.
How far in advance can you book a flight?
Trying to figure out how early you should book your flight? It’s possible to start comparing international airfares on Travelocity up to 12 months in advance. However, it does depend on the carrier as not all airlines release their prices that far out. According to our 2021 flight demand trends, last minute planners can still bag a bargain with some of the cheapest fares appearing 0-2 weeks prior to their travel dates.*According to flight demand on Travelocity.com from January to December 2021. Savings are subject to change based on departure location, date and destination.

Discover our best United flight from Boston BOS to St. Louis STL 

To find the best deals on flights to Boston from St. Louis with United, just enter your travel dates, filter by United, and hit search. You’ll find flights to choose from and can sort by price, flight duration, and arrival or departure time.  

 

Return flights from Boston BOS to St. Louis STL with United 

If you’re planning a round trip, booking return flights with United is usually the most cost-effective option. With airfares ranging from $254 to $302, it’s easy to find a flight that suits your budget. Prices and availability subject to change. Additional terms may apply. 

 

Book one-way United flights from Boston BOS to St. Louis STL 

A one-way ticket gives you much greater flexibility—allowing you to choose your return date, destination, and time whenever you’re ready. By booking in advance you can find great deals on one-way tickets too. Right now, a one-way United flight from Boston to St. Louis costs from $139. Prices and availability subject to change. Additional terms may apply. 

 

The easy way to find cheap flights to St. Louis STL from  Boston BOS with United 

To find a cheap United flight from Boston BOS to St. Louis STL, sort your search results by price or filter by budget. Thanks to Travelocity’s Price Match Promise, if you find a better airfare deal anywhere else within 24 hours, we’ll credit or refund the difference. 

 

How to find our best airfare deals on United flights from Boston BOS to St. Louis STL 

If you’re looking for cheap flights, it helps to be flexible when it comes to your travel dates. You’ll usually find lower cost tickets when you travel during quieter months such as June, or if you book a flight with a stopover. 

 

Find nonstop flights from Boston BOS to St. Louis STL with United 

If you’re keen to be on St. Louis soil fast, don’t waste time with a stopover—filter your search results to show direct United flights only. The journey takes around hour(s) min(s) – so you’ll be there before you know it. 

 

Flexible airline tickets for United flights from Boston BOS to St. Louis STL 

Make sure you’re not out of pocket if plans change by choosing a flexible ticket with penalty-free amendment and cancellation options. Use our ‘no change fee’ filter to see which flights have this option.  

 

There are a lot of reasons to book your flights to St. Louis STL from  Boston BOS with United on Travelocity 

At Travelocity our vast and up-to-the-minute inventory puts all of our best flight deals in one place. So, whether you’re traveling on business or jetting off with friends and family, you can trust Travelocity to get you there.

United Airports
Hop on a(n) United flight today by flying to many destinations out of these domestic and international airports:
Airport code
Country
Airport name
Number of flights
ORDUSAO'Hare Intl.227
DENUSADenver Intl.226
IAHUSAGeorge Bush Intercontinental136
IADUSAWashington Dulles Intl.100
SFOUSASan Francisco Intl.64
LAXUSALos Angeles Intl.23
EWRUSALiberty Intl.20
FRADEUFrankfurt Intl.19
NRTJPNNarita Intl.19
PEKCHNCapital Intl.16

Travelers ❤️ these 🏨 after their flight to St. Louis

Pear Tree Inn St. Louis Airport
Pear Tree Inn St. Louis Airport
2.5 out of 5
10810 Pear Tree Ln, St. Ann, MO
This hotel features a gym and a seasonal outdoor pool. Traveling on business? Take advantage of the business center, free WiFi in public areas, and free airport ...
9.2/10 Wonderful! (2,549 reviews)
"The staff and manager were very helpful and pleasant. Our only negative experience was not with the hotel, but the Burger King nearby. Extremely rude night server. She made it clear that old people are stupid and should just die and get it over with!"

Reviewed on May 1, 2025

Pear Tree Inn St. Louis Airport
Hilton St. Louis Airport
Hilton St. Louis Airport
3.5 out of 5
10330 Natural Bridge Rd, St. Louis, MO
This smoke-free hotel features 2 restaurants, a bar/lounge, and a 24-hour gym. Traveling on business? Take advantage of the express check-in, express check-out, ...
7.4/10 Good! (1,002 reviews)
"Garrett and Mariah are excellent guest services personnel who go above and beyond what one would expect."

Reviewed on Apr 30, 2025

Hilton St. Louis Airport
Wingate by Wyndham St. Louis Airport
Wingate by Wyndham St. Louis Airport
2.5 out of 5
10820 Pear Tree Lane, St. Ann, MO
This hotel features an outdoor pool and a gym. Traveling on business? Take advantage of the business center, free WiFi in public areas, and free airport shuttle. ...
9.2/10 Wonderful! (1,205 reviews)
"Great room and bath room was spotless."

Reviewed on Apr 30, 2025

Wingate by Wyndham St. Louis Airport
Lowest nightly price found within the past 24 hours based on a 1 night stay for 2 adults. Prices and availability subject to change. Additional terms may apply.
*Price based on the lowest price found within past 24 hours and based upon one night stay for two adults over the next thirty days. Prices and availability subject to change. Additional terms may apply.