Cheap Flights from Kansas City International to St Louis

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      Travellers and cabin class, 1 Adult, Economy
      Southwest Airlines

      Compare Kansas City International to St Louis flight deals

      Find the cheapest month or even day of the year to fly to St Louis

      Book the best St Louis fare with no extra fees

      Flight deals from Kansas City International to St Louis

      Looking for a cheap last-minute deal or the best return flight from Kansas City International Airport to St Louis Airport? If you want to travel next month, return fares start from $359. Find the lowest prices on one-way and return tickets right here.

      Find the cheapest month to fly from Kansas City International to St Louis

      We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Kansas City International to St Louis flights are currently cheapest in September.

      Direct flights from Kansas City International to St Louis

      Southwest Airlines

      Kansas City International to St Louis: Alternative routes

      Compare routes from Kansas City International to St Louis below. You may find an airport to fly into that's cheaper, faster, or easier than St Louis.

      Kansas City to St Louis: Flight information

      The things to know before you go.
      Cheapest flight found$357
      Cheapest month to flySeptember
      Average flight time1 hr, 4 mins
      Most popular airlineSouthwest Airlines
      Average flights per week26

      Finding cheap flights from Kansas City International to St Louis: Frequently asked questions

      The best price we found for a return flight from Kansas City International to St Louis is $357. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.
      1 hour and 4 minutes is the average flight time from Kansas City International to St Louis.
      Southwest Airlines flies direct from Kansas City International to St Louis.
      As of August 2026, there are 26 flights per week flying from Kansas City International to St Louis.
      The cheapest month to fly from Kansas City International to St Louis is usually September.
      After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from Kansas City International Airport to St Louis Airport on Thursday, 24 September 2026.
      Yes – the average flight time is 1 hour and 4 minutes.
      We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to St Louis but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.

      We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to St Louis is around 40 days in advance, so don’t leave your flight to the last minute.

      Currently, Frontier Airlines and Southwest Airlines offer the cheapest flight tickets to St Louis.

      Flying from Kansas City International Airport (MCI) to St Louis Airport (STL): what you need to know

      • Around 1 hour 5 minutes is how long you can expect to be in the air on a direct flight from Kansas City International Airport to St Louis Airport.

      • Kansas City and St Louis share the same timezone, UTC-6.

      • Flights from MCI to STL start from 05:25 — the first with Southwest Airlines. The latest departure is at 18:55 with Southwest Airlines. In total, there are 12 weekly Kansas City International Airport to St Louis Airport flights.

      • Arriving two hours before an international flight and one hour ahead of a domestic departure are golden rules for hassle-free flying. Make sure you're at the airport on time to board your MCI to STL flight.

      • During popular months like July, it's best to get to the airport earlier than normal. Arrive two hours before domestic departures and four hours ahead for an international flight when you travel during a peak period in general.

      • Flying into St Louis (and then seeing more of the United States!) is a snap with Southwest Airlines. This popular carrier has direct flights from Kansas City International Airport to St Louis Airport.

      • The airline with the highest passenger demand on this route is Southwest Airlines.

      • Southwest Airlines leads the way as the most punctual carrier for MCI to STL flights, with 85.54% of its services landing as scheduled.

      • Consider adding a stopover when booking your ticket from Kansas City International Airport to St Louis Airport. Just uncheck 'Direct flights only' to break up your trip, or visit a new city along the way. Check out these options between MCI and STL:

        • Chicago O'Hare International Airport

        • Nashville Airport

        • Chicago Midway Airport

      How to find the cheapest flights from Kansas City International Airport (MCI) to St Louis Airport (STL)

      • $227 is the best price for a one-way Kansas City International Airport to St Louis Airport flight. A return flight starts from $359. These prices may change depending on availability and demand.

      • To pick up cheap tickets from MCI to STL, book as early as you can. Airlines tend to offer lower prices when flights are first made available.

      • May is the cheapest month for flights from Kansas City International Airport to St Louis Airport. If you prefer to fly at a different time of year, the 'Whole month' tool will give you the lowest prices for every month.

      • You won't have to check every day to find out if fares have gone down when you create a Price Alert. We'll send you an update as soon as a special offer becomes available on cheap flights from MCI to STL.

      • Tailor your trip using filters. Select your ideal departure and arrival times, airlines and total journey duration. You can also sort the results by 'Best,' 'Cheapest' or 'Fastest' flights from Kansas City International Airport to St Louis Airport.

      Handy information about Kansas City International Airport (MCI)

      • You'll find MCI at 601 Brasilia Avenue.

      • 78% of flights that leave from Kansas City International Airport arrive at their destination on time.

      • To get to Kansas City International Airport from central Kansas City, it takes about 25 minutes if you're planning to drive. This depends on traffic though. It's approximately 24 kilometres from the airport to the city centre.

      • Planning to catch public transport? You can expect a journey time of around 1 hour.

      • Get your travels off to a leisurely start by staying near MCI. Whether you have an early flight from Kansas City International Airport to St Louis Airport or just don't like being rushed, these stays are the answer:

      Arriving at St Louis Airport (STL)

      When to fly to St Louis Airport (STL)

      • The quietest month for a flight from Kansas City International Airport to St Louis Airport is March, while July is the busiest. Pick the best time to visit St Louis based on whether you prefer a bustling atmosphere or a more laid-back vibe.

      • Before locking in your flight from Kansas City International Airport to St Louis Airport, think about the type of weather you like. July is the warmest month in St Louis, with temperatures ranging from 17ºC to 33ºC.

      • If you want cooler conditions, search for a cheap ticket from MCI to STL in January. Temperatures average between -7ºC and 8ºC then.

      Explore more of the United States

      • You've visited St Louis, now it's time to discover more of the United States. Travel around 418 kilometres north-east to Chicago to check off its popular sights. From Millennium Park to Art Institute of Chicago and Willis Tower, you've got a jam-packed schedule ahead.

      • Indianapolis is another sought-after destination in the United States and is around 370 kilometres east of St Louis. No journey is complete without a visit to Lucas Oil Stadium, Eiteljorg Museum and The Children's Museum of Indianapolis.

      Prices shown on this page are estimated lowest prices only. Found in the last 12 days.