STL - LHR

£206 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 17/10. 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

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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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

Tue, 18 Nov - Thu, 27 Nov
United Airlines Logo
18:43 - 11:15STL-LHR
10h 32m1 stop
United Airlines Logo
18:00 - 15:29LHR-STL
27h 29m1 stop
£389United Airlines
Find Deal
Tue, 28 Oct - Tue, 4 Nov
Delta Logo
12:14 - 08:45STL-LHR
15h 31m2 stops
Delta Logo
06:20 - 16:43LHR-STL
16h 23m2 stops
£389Delta
Find Deal
Tue, 11 Nov - Wed, 26 Nov
Delta Logo
12:49 - 08:45STL-LHR
13h 56m2 stops
Delta Logo
06:30 - 18:35LHR-STL
18h 05m2 stops
£390Delta
Find Deal
Sun, 1 Mar - Fri, 13 Mar
Air Canada Logo
16:05 - 20:35STL-LHR
22h 30m2 stops
Air Canada Logo
18:00 - 14:18LHR-STL
25h 18m2 stops
£394Air Canada
Find Deal
Wed, 11 Feb - Wed, 18 Feb
 Logo
16:05 - 13:00STL-LHR
14h 55m2 stops
 Logo
13:25 - 15:29LHR-STL
32h 04m2 stops
Thu, 15 Jan - Mon, 26 Jan
Iberia Logo
13:48 - 08:15STL-LHR
12h 27m1 stop
Iberia Logo
19:40 - 09:57LHR-STL
20h 17m2 stops
£413Iberia
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Sat, 11 Oct - Tue, 21 Oct
 Logo
13:30 - 06:30STL-LHR
11h 00m1 stop
 Logo
06:50 - 15:18LHR-STL
14h 28m2 stops
Fri, 17 Oct - Tue, 21 Oct
Air Canada Logo
09:15 - 06:30STL-LHR
15h 15m2 stops
Air Canada Logo
06:50 - 15:18LHR-STL
14h 28m2 stops
£419Air Canada
Find Deal
Mon, 17 Nov - Sun, 23 Nov
Iberia Logo
14:50 - 07:00STL-LHR
10h 10m1 stop
Iberia Logo
10:05 - 22:34LHR-STL
18h 29m1 stop
£424Iberia
Find Deal
Thu, 30 Oct - Mon, 3 Nov
British Airways Logo
19:54 - 11:35STL-LHR
10h 41m1 stop
British Airways Logo
08:20 - 16:40LHR-STL
14h 20m1 stop
£461British Airways
Find Deal

Everything you should know

Top airlines
United Airlines
Cheapest • from £389 (return)
KLM
Best reviews • 7.8 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to book
4 weeks
in advance
Our data shows that travellers who book at least 4 weeks in advance save around 32% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
October
Cheapest • 20% price drop
May
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Cheapest return fare
£389
Typical prices: £547-832
United Airlines
Tue 18/11Thu 27/11
STL - LHR • 1 stop
Cheapest one-way flight
£206
Typical prices: £366-399
Multi-carrier
Fri 17/10
STL - LHR • 3 stops
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KAYAK searches hundreds of sites at once to find you the best travel deals.
We hope you love your trip to Heathrow!
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?

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 Tuesday, as we generally find the cheapest rates on that day for this route. On the other hand, Friday is the most expensive day to fly from St. Louis to London Heathrow Airport. For your return ticket, we recommend flying on a Wednesday 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 £544 (return) on average. On the other hand, the most expensive months are June and December, where the average cost of round-trip tickets is £934 and £824 respectively.

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 4 weeks before departure, which saves you about 32% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 5 weeks before departure.

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

Low seasonJanuary
Cheapest flight£206
Best time to beat the crowds (10% less expensive on average)
Most popular time to fly (7% 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 £280 for a one-way ticket and £528 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?

    We unfortunately don’t have that data for this specific 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 £789 and an overall rating of 7.8, KLM is the most popular choice. Virgin Atlantic is also a great choice for the route, with an average price of £750 and an overall rating of 7.4.

  • 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.
7.8
KLMOverall score based on 1385 reviews
7.2Entertainment
8.4Crew
7.7Comfort
7.3Food
7.8Boarding
Airline reviews

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.

2.0 MediocrePeter, Aug 2025SAN - AMS
Read more KLM reviews

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

Cabin crew were excellent, very proffesional, polite and friendly, in flight snack was underwhelming, a packet of cheese biscuits, im sure KLM could run to a sandwich!

Legroom not all it could be, especially when the seat in front is reclined. Otherwise it was good, food and beverage were nice.

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.

Food was excellent. Service was very good. Staff was very helpful to all passengers.

The crew was excellent as ever on Virgin. The special meal was poor unfortunately. More significantly when we arrived at Manchester Airport there was no air bridge provided and we had to exit the plane down a rickety stair case. This is unacceptable for a transatlantic flight. Whilst I understand that this is the airport’s fault at the end of the day the airline is responsible for our transportation and needs to do something.

Super friendly and helpful staff, from check-in desk to cabin crew.

For the price, it was a really good experience. There was no entertainment on board, so I couldn't really rate this, and I didn't order a meal. I appreciated that there was a free glass of wine.

Short flight. Everything was fine except the flight was delayed twice for a total of an hour.

My flight from New York to Canada and Canada to Brisbane was canceled, so I had to take united airlines instead flight from New York to Dubai then layover in Dubai 8 hours then from Dubai to Brisbane it was extremely difficult for me , it was a nightmare flying with Canadian airlines unfortunately.

I found the boarding easy and my seat was very comfortable as I had a lot of leg room. I am not too happy that I no longer have lounge access even though I used to get it with my TD credit card.

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

Real smooth and easy, Real good leg room in coach!

There labor disputes cancelled my flight less than 24 hours before my boarding time but there customer service/website was easy enough to navigate and they rebooked me for no upcharge.

Re luggage I carried a backpack only. I did not check any bags in. However there were other passengers with carry on luggage going in the plane. My question is why are others allowed to have a carry on luggage inside the plane? Shouldn’t they have dropped it off at the gate? I’m asking because I could have brought the same thing instead of a backpack only. Please clarify for future reference. Thank you.

Like the service. Very hard to communicate or contact when have problems

Very bad, flight was cancelled due to strike and staff was unable to rebook us

The seating has become ridiculous… like a contest to see how narrow and short they can be made- forcing anyone over 5’1 to pay more to not be twisting oneself into a pretzel. Really insane- would have thought BA was better than this. Frankly- it cancels out a lot of the positive aspects.

flight was delayed from BWI to London - missed my connecting flight & then connecting flight (also British Air) was delayed - food is awful, TV & movie selection is great

Super tight economy class. My knees were hitting the back of seat in front of me (I'm only 5'6"). My small backpack (sized according to their required dimensions) would not fit under the seat in front of me because there is a box (is that the life jacket?) in the way. Over all, extremely uncomfortable. I forgive the tasteless food, but the tight seating was torture

Didn’t fly with them as someone had cancelled my flight

Online check-in 24 hours in advance something seems not so easy to check in to pick seats and to print a boarding pass

I like the crew, very welcoming. Food can be better. The seat arms don’t go up so. I could use the empty seat next to mine to relax better. 3hrs delay 😠

Boarding was efficient and quick, crew was very attentive, seats were comfortable.

Everything was very good! I personally struggled with the heat in the cabin for the first 2 hours

Very caring crew on board. Didn’t have dinner as I was sleeping. Was seating in the emergency row so I had comfortable leg room

Had a nice little suite although I couldn’t close the door (but I didn’t ask anyone to help). 5K is a nice seat and very private (you look in on first class). Enjoyable flight and nice crew.

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

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