STL - BOI

$139 Find Cheap Flights from St. Louis to Boise - Compare and Save

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from St. Louis to Boise departing on 9/20. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
$260
Typical prices: $278-$526
Frontier
Thu 9/10Thu 9/17
STL - BOI • 1 stop
Cheapest one-way
$139
Typical prices: $386-$455
Frontier
Sun 9/20
STL - BOI • 2 stops
Top airlines
Cheapest • from $260 (round-trip)
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
Not available
There are currently no direct flights between St. Louis and Boise. You'll need at least 1 connection.
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $386 (round-trip)
Shortest trip • 5h 35m (one-way)
Insights
Insights
Insights
Insights
When to travel
Cheapest • 19% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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We hope you love your trip to Boise!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from St. Louis to Boise (STL-BOI)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Boise that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from St. Louis to Boise

Thu, Sep 10 - Thu, Sep 17
Frontier Logo
12:17 pm - 1:55 pm
STL
-
BOI
26h 38m
1 stop
Frontier Logo
2:50 pm - 11:27 am
BOI
-
STL
19h 37m
1 stop
$260Frontier
Thu, Sep 10 - Thu, Sep 17
Frontier Logo
12:17 pm - 1:55 pm
STL
-
BOI
26h 38m
1 stop
Frontier Logo
2:50 pm - 11:27 am
BOI
-
STL
19h 37m
1 stop
$294Frontier
Thu, Sep 24 - Tue, Sep 29
Delta Logo
2:25 pm - 11:58 pm
STL
-
BOI
10h 33m
2 stops
Delta Logo
6:45 am - 5:37 pm
BOI
-
STL
9h 52m
2 stops
$364Delta
Fri, Sep 11 - Thu, Sep 24
Southwest Logo
6:05 pm - 10:40 pm
STL
-
BOI
5h 35m
1 stop
Southwest Logo
2:55 pm - 11:15 pm
BOI
-
STL
7h 20m
1 stop
$369Southwest
Fri, Sep 11 - Sat, Sep 12
Southwest Logo
6:00 pm - 11:55 pm
STL
-
BOI
6h 55m
1 stop
Southwest Logo
3:25 pm - 10:25 pm
BOI
-
STL
6h 00m
1 stop
$369Southwest
Wed, Sep 9 - Sat, Sep 12
American Airlines Logo
7:00 am - 1:00 pm
STL
-
BOI
7h 00m
1 stop
American Airlines Logo
7:02 am - 2:44 pm
BOI
-
STL
6h 42m
1 stop
$369American Airlines
Thu, Aug 27 - Mon, Aug 31
American Airlines Logo
9:32 am - 2:29 pm
STL
-
BOI
5h 57m
1 stop
American Airlines Logo
12:12 pm - 8:26 pm
BOI
-
STL
7h 14m
1 stop
$369American Airlines
Thu, Sep 24 - Tue, Sep 29
Delta Logo
2:25 pm - 11:58 pm
STL
-
BOI
10h 33m
2 stops
Delta Logo
6:45 am - 5:37 pm
BOI
-
STL
9h 52m
2 stops
$409Delta
Fri, Sep 11 - Sun, Sep 13
United Airlines Logo
1:36 pm - 9:31 pm
STL
-
BOI
8h 55m
2 stops
United Airlines Logo
5:40 pm - 11:31 pm
BOI
-
STL
4h 51m
1 stop
$428United Airlines
Fri, Aug 28 - Fri, Sep 4
United Airlines Logo
1:36 pm - 5:58 pm
STL
-
BOI
5h 22m
1 stop
United Airlines Logo
12:24 pm - 10:00 pm
BOI
-
STL
8h 36m
1 stop
$451United Airlines
Booking Insights

KAYAK's insights & trends for St. Louis to Boise flights

Get data-powered insights and trends into flights from St. Louis to Boise to help you find the cheapest flights, the best time to fly and much more.

How much is a round-trip flight from St. Louis to Boise?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from St. Louis to Boise departing in September.

Flight prices are below average for this route right now.

Flights to Boise from St. Louis usually cost between $357 and $676 in September.
The lowest price found in the past 5 days was $260 on Frontier (Sep 10-Sep 17).

What is the cheapest month to fly from St. Louis to Boise?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from St. Louis to Boise, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from St. Louis to Boise is January, where tickets cost $359 (return) on average. On the other hand, the most expensive months are February and March, where the average cost of round-trip tickets is $566 and $538 respectively.

Good to know

Low season

February

Cheapest flight

$139
Best time to beat the crowds but there is an average 27% increase in price.
Most popular time to fly and prices are also 9% lower on average.
Flight from St. Louis to Boise

When to book flights from St. Louis to Boise

Are your dates flexible? Find out the best times to travel from St. Louis to Boise based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from St. Louis to Boise

  • What is the cheapest flight from St. Louis to Boise?

    In the last 5 days, the lowest price for a flight from St. Louis to Boise was $139 for a one-way ticket and $260 for a round-trip.

  • Do I need a passport to fly between St. Louis and Boise?

    Even though you are not required to have a passport, keep in mind that an official ID is needed to board the airplane.

  • Which airports will I be using when flying from St. Louis to Boise?

    When flying out of St. Louis you will be using Lambert-St Louis. You will be landing at Boise, also known as Boise Air Term. Gowen Fld.

  • Which aircraft models fly most regularly from St. Louis to Boise?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from St. Louis to Boise?

    oneworld, SkyTeam, and Star Alliance are the airline alliances operating flights between St. Louis and Boise, with oneworld being the most commonly used for this route.

  • Which is the best airline for flights from St. Louis to Boise, Southwest or Delta?

    The two airlines most popular with KAYAK users for flights from St. Louis to Boise are Southwest and Delta. With an average price for the route of $471 and an overall rating of 8.0, Southwest is the most popular choice. Delta is also a great choice for the route, with an average price of $406 and an overall rating of 7.8.

  • How does KAYAK find such low prices on flights from St. Louis to Boise?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from St. Louis to Boise.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from St. Louis to Boise?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Boise from St. Louis is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from St. Louis to Boise?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Boise with an airline and back to St. Louis with another airline. Booking your flights between St. Louis and BOI can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from St. Louis to Boise?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Boise from St. Louis up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 4 airlines serving from St. Louis to Boise

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to Boise. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from St. Louis to Boise? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4229 reviews
8.1Boarding
7.5Entertainment
8.0Comfort
7.0Food
8.6Crew
Airline reviews

The flight was delayed due to earlier issues at other airports. The crew was excellent & made it a good trip.

6.0 GoodJeremy, Aug 2026
STL - PHL
Read more Southwest reviews

The flight was delayed due to earlier issues at other airports. The crew was excellent & made it a good trip.

Snacks are always pretzels. Why can't you also offer peanuts ?

Only downside was the legroom and seat width, which is always a problem unless I spend more for a premium seat.

Very good. Sad to learn Southwest is going start to charge for bags

Exceptional crew! Friendly and professional. Pleasant attitude and treated everyone with respect.

The flight was promptly on schedule and Southwest delivered everything they promised. No excuses for any shortfalls just 100% ownership of their responsibilities and business. The boarding and seating policy is a complete shambles. What started out as a great idea when Southwest first hit the market has been turned into a disaster due to the lack of integrity in many of the people who fly Southwest and take advantage of Southwest generosity at the expense of their fellow passengers.

Crew was excellent - Plane was fine. Media was good, could use more kid shows; Not a fan of the brownie brittle -- snack could be slightly better.

Left on time and arrived early. Brand new plane and no parts missing. Comfortable seats. The actual Captain spoke prior to the flight and reassured everyone about safety. Crew was so nice and fun. Perfect flight!

Everything went smoothly and the plane wasn’t full. It was delayed though. The delay was increased due to a crew change which was frustrating.

Love Southwest! Always a good trip with a happy crew who goes out of their way to be kind and fun.

Your survey needs a N/A option. I didn’t use the entertainment or eat food.

Flight was delayed multiple time and for more than 1 hr. My onward flight from BOS to MCI was also delayed. These delays have caused me so much inconvenience and Delta does nothing to ensure flights take off on time. No one knew why the inbound flight was delayed and what was the issue.

I missed the flight because the Minneapolis flight was 49 minutes LATE, and the Boise flight LEFT 24 minutes EARLY!

From checking to boarding, it was a seamless experience. The service agents were so helpful. The flight crew was so pleasant.

Great flight with Delta! Boarding was quick and easy, the amenities were solid, and the plane was in great shape. The flight attendants had a fun, lively energy while staying professional. All in all, a smooth trip — even managed to catch up on some rest. Thanks, Delta!

Having to up charge for a seat assignment is not good. Delta can do better

My flight was canceled after being rescheduled for four days canceling my trip. Kayak and everyone affiliated with it I.e the airlines, and just fly have been excruciating to deal with. My trip to visit family had to be canceled as there was no way to make it. I am furious at all of you.

They delayed our flight because of bad weather in NY which was completely understandable. Then they cancelled our flight and a later flight that evening. The earliest we could fly was the next morning. We ended up buying last minute tickets on another airline and made it home slightly delayed but safely that evening. Delta kept saying it was weather related but if that was the case how did we make it back on another airline? The weather in NY was cloudy but not bad.

The plane smelled like a sewer. Multiple passengers complained. It’s a safety and quality issue to clean these planes.

We were delayed 2 hours leaving STL. I had 20 mins from when we landed in SLC terminal A to make it to SLC terminal B. I had to actually run! thankfully I made my flight but 3/4 legs were delayed to some capacity.

I almost missed my connection in Chicago due to having to wait on a gate to be open I am assuming. Having to run from E terminal to C terminal and I barely made it there before they closed the door. This may not be the actual airline's fault it's crazy how there is so little time between flight especially when they are placed so far apart in the airport.

Our flight was great with an unexpected upgrade. However, four days into our travel we are still without a piece of luggage. The bag tracker has not been accurate, the airline is not communicating with me or the luggage delivery service and no one is willing to take responsibility or guarantee any kind of support or reimbursement. Unfortunately, we do not have the option to easily shop to replace items as we are currently on a cruise. I have been very disappointed by United Airlines response.

Fine not above and beyond as I had a connection that was delayed due to maintenance

HORRIBLE, my initial flight was cancelled, they made me pay $200 extra dollars and that got cancelled as well! After 6 cancellations I decided to get a refund because I needed to get home to my babies. Out of $1000+ dollars they offered me only $40 in refund! Totally unacceptable! The flight that they cancelled I was able to fly it on another airline. I had to spend $400 on one way tickets just to get home! I’m still getting the runaround.

Flight was delayed. De-icing took a while. When we landed had to wait for another plane to vacate our gate. Just an overall bad experience.

Flight was delayed only slightly before takeoff due to traffic control. However, the flight arrived early to ORD. Good flight. United has been very reliable for me.

Our flight was understandably diverted to a small regional airport in Laramie, Wyoming due to weather conditions, which I fully recognize and appreciate. However, the low rating stems from the experience that followed: passengers remained on board for over an hour without the option to deplane and stretch, despite the aircraft being stationary. Although the pilot opened the cabin door, only he was permitted to exit. Meanwhile, passengers grew increasingly uncomfortable as warm summer air entered the cabin through the open door, and being in the second row meant we were impacted immediately. While the flight attendants made efforts to keep everyone at ease, I believe allowing passengers to deplane briefly, given the extended delay, would have significantly improved the overall experience.

Overall a very poor experience - booked premium economy tickets but due to last minute flight delays , all my itinery went for a toss and had to fly economy class with no access to lounge or any compensation by united airlines to make up for the flight delays . i had expected better experience than that from united.

Onboarding - it would be great to see on the screen what group they were boarding. It was very confusing on who was boarding (even though they called it out) they were not clear and the space to board was strange.

Older plane. Food was really bad, almost not worth the effort. Huge difference with European based airlines.

My luggage was not sent with us. Not sure if this is Envoy Air responsibility but that was a very BAD experience

American delayed the flight for a crew rest period. The delay occurred late in the evening - the earliest i can find is 10:20 pm. With a 6 am flight anyone on the flight would have already have been asleep (unless you are insane, a vampire or on drugs) and at least for me i was already on the way to the airport at 445 am the next morning when i discovered they delayed the flight until 9 am. Given the incoming flight was in the air at 6 pm the evening before this should have been figured out a lot more timely that was there only crew to use. Just frustrating given there is no consideration for customer experience anymore in flying.

Good crew and flight was on time. It’s a small plane with limited overhead luggage space. They said the overhead space was full and I had to check my bag. There was still space when I got on. Waiting for my checked luggage added 30 minutes to my trip. Not the end of the world but also not great.

the plane was so hot!! the air-conditioning was barely blowing. The flight was delayed, and we had to sit on the hot plane before take off for an extended amount of time, waiting on international passengers. Would not have been so bad if it was not so hot. They said it would get better after take off, but it did not.

Trip delayed for 2 hours because of rain. We boarded and have to get down the flight and reboard again.

No enough space plus only allowing one laggage instead of two like other airlines.

Qatar airways ,boarding arrangements at Hamid international airport could been better

Two flight changes before the scheduled flight. On the day of the flight, the flight was delayed, which caused the connecting flight to be missed. Then, I was directed to another airport (CUN) and traveled to Tulum. American gave a $12 voucher for lunch. The least expensive item on the menu at a Mexican restaurant was $9.99. Driving to Tulum was a bad auto crash, and traffic was delayed two-plus hours. The bottom line is that we should have been at the hotel at noon, but it ended up at 11:30 PM.

Miami lounges were overcrowded and we were unable to get in. We only had a short time. But the banks are too tight in all American hubs

Overall boarding and debarking is a joke. I dont even bring luggage anymore on trips because you can never allow them to be place then in the overhead bin or you have to pay or you check them which is even worse having to wait for your luggage on the tarmac.

Everything you need to know for your flight from St. Louis to Boise

Information on your arrival and departure airports