STL - LHR

£269 Find Cheap Flights from St. Louis to London Heathrow Airport

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 Heathrow departing on 5/5. 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

KAYAK searches hundreds of travel sites at once for deals on flights to London Heathrow Airport

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to London, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to London, as well as popular online travel agencies
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41,299,237 searches in the past 7 days on KAYAK

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Everything you should know

Cheapest return fare
£490
Typical prices: £552-£978
United Airlines
Sun 18/1Wed 1/4
STL - LHR • 2 stops
Cheapest direct flights
£499
Finnair
Sun 26/4Wed 6/5
STL - LHR • Direct
Top airlines
Delta
Cheapest • from £492 (return)
KLM
Best reviews • 7.7 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to book
2 weeks
in advance
Our data shows that travellers who book at least 2 weeks in advance save around 25% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
October
Cheapest • 21% price drop
May
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches hundreds of sites at once to find you the best travel deals.
We hope you love your trip to Heathrow!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from St. Louis to Heathrow (STL-LHR)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for return flights from St. Louis to Heathrow 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 return flight deals from St. Louis to Heathrow

Sun, 18 Jan - Wed, 1 Apr
United Airlines Logo
11:20 - 09:20
STL
-
LHR
16h 00m2 stops
United Airlines Logo
06:30 - 13:30
LHR
-
STL
13h 00m1 stop
£490United Airlines
Wed, 22 Apr - Mon, 27 Apr
Iberia Logo
22:00 - 12:05
STL
-
LHR
8h 05mdirect
Iberia Logo
19:25 - 21:48
LHR
-
STL
32h 23m2 stops
£490Iberia
Sun, 26 Apr - Wed, 6 May
British Airways Logo
19:03 - 12:30
STL
-
LHR
11h 27m1 stop
British Airways Logo
16:25 - 19:30
LHR
-
STL
9h 05mdirect
£491British Airways
Wed, 8 Apr - Thu, 16 Apr
Delta Logo
13:35 - 08:50
STL
-
LHR
13h 15m2 stops
Delta Logo
06:30 - 16:45
LHR
-
STL
16h 15m2 stops
£492Delta
Sun, 10 May - Fri, 22 May
Multiple Airlines Logo
09:30 - 10:00
STL
-
LHR
18h 30m2 stops
Multiple Airlines Logo
06:30 - 13:30
LHR
-
STL
13h 00m1 stop
£493Multiple Airlines
Thu, 15 Jan - Mon, 26 Jan
Lufthansa Logo
13:15 - 11:15
STL
-
LHR
16h 00m1 stop
Lufthansa Logo
20:15 - 17:43
LHR
-
STL
27h 28m2 stops
£494Lufthansa
Sun, 10 May - Fri, 22 May
British Airways Logo
22:00 - 12:05
STL
-
LHR
8h 05mdirect
British Airways Logo
14:25 - 20:02
LHR
-
STL
11h 37m1 stop
£495British Airways
Tue, 24 Feb - Mon, 2 Mar
Multiple Airlines Logo
08:17 - 07:10
STL
-
LHR
16h 53m2 stops
Multiple Airlines Logo
19:30 - 21:40
LHR
-
STL
32h 10m2 stops
£496Multiple Airlines
Mon, 12 Jan - Mon, 19 Jan
United Airlines Logo
13:15 - 05:55
STL
-
LHR
10h 40m1 stop
United Airlines Logo
15:30 - 15:29
LHR
-
STL
53h 59m2 stops
£498United Airlines
Sun, 26 Apr - Wed, 6 May
Finnair Logo
22:00 - 12:05
STL
-
LHR
8h 05mdirect
Finnair Logo
16:25 - 19:30
LHR
-
STL
9h 05mdirect
£499Finnair
Booking Insights

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

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

How much is a return flight from St. Louis to London Heathrow Airport?

This analysis is based on the cheapest return trip price found on KAYAK in the last 12 months by searching for a flight from St. Louis to London Heathrow Airport departing in January.

What’s the cheapest day of the week to fly from St. Louis to London Heathrow Airport?

The average price of all round-trip flights from St. Louis to London Heathrow Airport clicked on KAYAK for each day over the last 12 months.

If your flying dates are flexible, you should consider flying to London Heathrow Airport on a Thursday, as we generally find the cheapest rates on that day for this route. On the other hand, Monday is the most expensive day to fly from St. Louis to London Heathrow Airport. For your return ticket, we recommend flying on a Sunday and avoiding Thursdays for the best deals.

What is the cheapest month to fly from St. Louis to London Heathrow Airport?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from St. Louis to London Heathrow Airport, 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 London Heathrow Airport is October, where tickets cost £525 (return) on average. On the other hand, the most expensive months are June and July, where the average cost of round-trip tickets is £941 and £784 respectively.

Can I save money by flying with a stopover from St. Louis to London Heathrow Airport?

The average return price for all direct flights, flights with one stopover, and flights with two stopovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of £603, prices are generally cheapest when you fly direct.

How far in advance should I book a flight from St. Louis to London Heathrow Airport?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from St. Louis to London Heathrow Airport, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from St. Louis to London Heathrow Airport, you should book around 2 weeks before departure, which saves you about 25% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 8 weeks before departure.

Good to know - Cheap tickets from St. Louis to London Heathrow Airport

Low seasonJanuary
Cheapest flight£269
Best time to beat the crowds but there is an average 3% increase in price.
Most popular time to fly (11% more expensive on average)
Flight from St. Louis to London Heathrow Airport

When to book flights from St. Louis to Heathrow

Are your dates flexible? Find out the best times to travel from St. Louis to Heathrow based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated return price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or returns 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 St. Louis to London Heathrow Airport flights

  • What is the cheapest flight from St. Louis to London Heathrow Airport?

    In the last 3 days, the lowest price for a flight from St. Louis to London Heathrow Airport was £269 for a one-way ticket and £490 for a return.

  • Which airports will I be using when flying from St. Louis to London Heathrow Airport?

    On your way to London Heathrow Airport, you’ll fly out from Lambert-St Louis. You’ll be landing at London Heathrow.

  • Which aircraft models fly most regularly from St. Louis to London Heathrow Airport?

    The Boeing 787-8 Dreamliner is the aircraft model that flies most regularly on the St. Louis to London Heathrow Airport flight route.

  • Which airline alliances offer flights from St. Louis to London Heathrow Airport?

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

  • Which is the best airline for flights from St. Louis to London, KLM or Virgin Atlantic?

    The two airlines most popular with KAYAK users for flights from St. Louis to London are KLM and Virgin Atlantic. With an average price for the route of £550 and an overall rating of 7.7, KLM is the most popular choice. Virgin Atlantic is also a great choice for the route, with an average price of £584 and an overall rating of 7.5.

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

    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 London Heathrow Airport.

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

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

  • What is the Hacker Fare option on flights from St. Louis to London Heathrow Airport?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional return ticket. You could then fly to London Heathrow Airport with an airline and back to St. Louis with another airline.

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

    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 London Heathrow Airport 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 flying from St. Louis to Heathrow

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to London. 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 Heathrow? 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.
7.7
KLMOverall score based on 1432 reviews
7.8Boarding
7.6Comfort
7.1Entertainment
8.4Crew
7.2Food
Airline reviews

Delay and had to run between flight to get my connection due to this delay but besides that the overall experience was ok. I arrived with just an hour of delay.

8.0 ExcellentKevin, Nov 2025
HEL - AMS
Read more KLM reviews

Delay and had to run between flight to get my connection due to this delay but besides that the overall experience was ok. I arrived with just an hour of delay.

They forgot to serve food and the crew was very unfriendly. Never experienced such a bad KLM flight. Usually fly from Toronto. New York was different.

Over 1 Hr delay. No APU so no AC on ground. Plane was hot during boarding and then they closed the doors over 20 minutes before engine start so interior of plane was steamy hot and stuffy. Could have been helped by opening doors until ready to depart.

Ad experience - been flying many years with them but they are losing out to other carriers with their service and bagage / seating policy. My 2 12-yo kids were not placed with the parent. Absurdity.

KLM remains a quality flag carrier airline which maintains its standards whilst all their competitors are lowering theirs.

Our first flight was delayed so we missed our connecting flight. However it was easy to book a later flight on their app.

My flight was delayed by 6 hours then I missed BOTH of my connecting flights, I then had to stay in the AIRPORT at JFK because soooooo many people also suffered from missing flights and there was no hotels available. I would like to be compensated for this experience! I had to stay in the airport for over 16 hours!

Klm start boarding while somw air issue in the plan

I appreciate that KLM was proactive in informing me of the 2 hour delay which enabled me to replan my travel. It was a bit stressful not knowing whether my connection from Montreal to Ottawa was happening. But the ground and air crew did a good job at comforting and assuring me.

Cabin crew professional, polite and friendly, boarding was seemless, but come on KLM surely you can do better than a pack of cheesy biscuits as an inflight snack

Food has been disappointing in both legs of flight to india

Great staff great experience, made a 2 hour delay very bearable

Great staff, great experience, made a 2 hour delay very bearable

Food was the worst I’ve had on a VA flight. Normally it’s a lot better

I was my pleasure to fly virgin on my birthday for my first solo trip ever 🫶🏼

These are one of the older seat arrangements facing away from the windows! Not particularly convenient sets. No storage spaces. NO COAT HANGING HOOKS. Inconvenient business class seat compared to any other airlines of similar class. Staff are excellent! Extremely professional, friendly. Food is good too.

Overall, flight was excellent but check in was very slow for Premium Economy. Economy queue was shorter but we weren't allowed to use it.

The staff was not very polite but the flight was very very nice and comfortable and the entertainment was great

Great crew - old style upper class seats on the older fleet now feels dated

Premium economy more comfortable than economy, but not by much. Did was awful, do not try the omelette. Flight crew were helpful. Flight was delayed by over an hour. Overall but bad, arrived safely and thank God.

It was just fine. I managed to make all my connection too sbut had trouble in Munich with no wheel chair and trouble trying to get help from the airport people to get to the other terminal for my flight. Finally a wonderful lady Amelia, helped me to make my flight connection Timon with zero time to spare.

Over 40 years ago my AC return flight was canceled, during this last summer the same thing happened. AC denied everything Canadian like paying for accommodations and basic necessities. So why would I ever want to fly AC again? This last flight my wife took the return flight had problems and left late, so I guess they are getting better. However I have no faith in this airline so I drove to this last destination! I'll never fly AC again!!!

Great check in process in LA and good service The check in process as well as at the gate is way better in the US versus canada 🇨🇦

Super experience. Earlier than schedule departure and arrival. Baggage handling was very good

Allow me to book extra bag check in as free though I packed in 1 luggage but that was 7 LBS overweight so make another bag to free check in.

I would like to get my money back. I flight was 4 hours late on the way to detroit, And same on my way back to Brussels they cancelled my flight and give me an other ticket and i had to wait 5 hours.

All attendents were very efficient, pleasant and happy. Everything went smoothly. The seats could have been wider. There could have been more free food instead of just one small bar.

My seat was one of those that couldn't recline, but the problem was that it was abnormally upright, so the headrest actually made the seat concave, which was uncomfortable and hard on my lower back. I had to ball my jacket up and use it as lumbar support. goodness I had it with me.

I hope they were able to assign my preferred seat on my connecting flight. Wasn’t sure if it was language issue or they just can’t.

Flight cancelled. Major disruption to our travel. Do not use Air Canada from KC. To few flights.

Check in was was and the agent was very friendly and helpful The lounge was nice...boarding was straight from the lounge Everything worked at our seats, and video entertainment was good ..food was mediocre

The flight was excellent in World Travellor plus. Well worth the extra money. Boarding at Phoenix was the usual poorly organized event. Very stressful.

Although business class, the seating was really cramped. The food was so so.

Smooth trip no turbulence which is always a bonus for me lol! In cattle class so an element of being a bit squished (but not as bad as other shorter haul airlines) smaller plane than the one we flew out on and entertainment system wasn’t as modern but still definitely passed the time. Lovely crew x

Flying on the Boeing 787 from Seattle to London was everything that I expected. Every thing was great.

Seat pitch is not enough to eat comfortably. When seat in front is reclined, your screen comes closer to your face. Ryanair seats are actually more comfortable.

The leg from Portland to Heathrow was great for a business class ticket. The BA leg from Heathrow to Lisbon was terrible. Basically coach seating with an empty seat between you and next passenger. Absolutely no leg room. Should not have been charged for business class and it was a 3 hour flight.

The flat beds. Other than that, the place was not clean.

Moved me away from my family and refused to fix it.

I have always been pleased with their service. Would not change a thing

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

Information on your arrival and departure airports