STL - LHR

$284 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 10/1. 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.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to London.
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 20% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Flights Deals
Useful Info
Flights 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 round-trip 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 round-trip flight deals from St. Louis to Heathrow

Wed, Oct 1 - Wed, Oct 8
 Logo
9:15 am - 6:30 amSTL-LHR
15h 15m2 stops
 Logo
6:50 am - 7:57 pmLHR-STL
19h 07m2 stops
Tue, Sep 9 - Fri, Sep 19
 Logo
9:15 am - 6:30 amSTL-LHR
15h 15m2 stops
 Logo
6:50 am - 7:57 pmLHR-STL
19h 07m2 stops
Tue, Oct 14 - Fri, Oct 31
United Airlines Logo
1:30 pm - 9:35 amSTL-LHR
14h 05m1 stop
United Airlines Logo
6:30 am - 2:55 pmLHR-STL
13h 25m1 stop
$624United Airlines
Find Deal
Mon, Sep 1 - Wed, Sep 17
British Airways Logo
7:41 pm - 2:25 pmSTL-LHR
12h 44m1 stop
British Airways Logo
2:25 pm - 9:53 pmLHR-STL
13h 28m1 stop
$626British Airways
Find Deal
Sun, Oct 19 - Fri, Oct 31
United Airlines Logo
12:25 pm - 8:20 amSTL-LHR
13h 55m1 stop
United Airlines Logo
6:30 am - 2:55 pmLHR-STL
13h 25m1 stop
$629United Airlines
Find Deal
Sat, Oct 18 - Thu, Oct 30
Air Canada Logo
4:05 pm - 6:35 amSTL-LHR
32h 30m1 stop
Air Canada Logo
1:25 pm - 5:14 pmLHR-STL
32h 49m2 stops
$631Air Canada
Find Deal
Tue, Aug 19 - Thu, Aug 28
Air Canada Logo
1:30 pm - 10:00 amSTL-LHR
14h 30m1 stop
Air Canada Logo
6:50 am - 3:21 pmLHR-STL
14h 31m2 stops
$633Air Canada
Find Deal
Sat, Aug 23 - Mon, Sep 1
British Airways Logo
4:19 pm - 6:50 amSTL-LHR
32h 31m1 stop
British Airways Logo
7:30 pm - 6:30 pmLHR-STL
29h 00m2 stops
$646British Airways
Find Deal
Sat, Jul 19 - Tue, Jul 29
Iberia Logo
3:08 pm - 6:25 amSTL-LHR
33h 17m1 stop
Iberia Logo
2:25 pm - 8:19 pmLHR-STL
11h 54m1 stop
$683Iberia
Find Deal
Thu, Aug 28 - Mon, Sep 1
Iberia Logo
1:15 pm - 8:05 amSTL-LHR
12h 50m1 stop
Iberia Logo
6:15 pm - 8:58 pmLHR-STL
32h 43m2 stops
$730Iberia
Find Deal
Useful Info

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.

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.

For St. Louis to London Heathrow Airport, Thursday is the cheapest day to fly on average and Friday is the most expensive. Flying from London Heathrow Airport back to St. Louis, the best deals are generally found on Thursday, with Saturday being the most expensive.

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 $807 (return) on average. On the other hand, the most expensive months are June and December, where the average cost of round-trip tickets is $1,284 and $1,154 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. For the absolute cheapest price, our data suggests you should book 9 weeks before departure.

Good to know

Low seasonFebruary
High seasonMay
Cheapest flight$284
Best time to beat the crowds but there is an average 1% increase in price.
Most popular time to fly with an average 3% increase in price.
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 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 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 $284 for a one-way ticket and $595 for a round-trip.

  • Do I need a passport to fly between St. Louis and London Heathrow Airport?

    A passport is required to fly from St. Louis to London Heathrow Airport.

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

    St. Louis and London Heathrow Airport are both served by 1 main airport. You will leave St. Louis from Lambert-St Louis and will be arriving 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, SkyTeam, and oneworld are the airline alliances operating flights between St. Louis and London Heathrow Airport, with SkyTeam being the most commonly used for this route.

  • What is the most popular layover when flying to London Heathrow Airport from St. Louis?

    Chicago is the most popular layover city among KAYAK users traveling from St. Louis to London Heathrow Airport.

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

    The two airlines most popular with KAYAK users for flights from St. Louis to London are Delta and KLM. With an average price for the route of $992 and an overall rating of 8.0, Delta is the most popular choice. KLM is also a great choice for the route, with an average price of $896 and an overall rating of 7.8.

  • 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 travelers 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 round-trip ticket. You could then fly to London Heathrow Airport with an airline and back to St. Louis with another airline. Booking your flights between St. Louis and LHR 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 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.

Top 5 airlines serving 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.
7.4
United AirlinesOverall score based on 8801 reviews
6.6Food
8.1Crew
7.0Entertainment
7.7Boarding
7.3Comfort
Airline reviews

Evidently, my seat had the only broken TV. I couldn’t plug it in, get it to come on, or watch anything, and of course, no one could fix it while we were on the plane. The service was good and the boarding was quick

8.0 ExcellentStacie, Jun 2025ORD - ALB
Read more United Airlines reviews

Evidently, my seat had the only broken TV. I couldn’t plug it in, get it to come on, or watch anything, and of course, no one could fix it while we were on the plane. The service was good and the boarding was quick

United airlines, mediocre at best. No issues , nothing great . Worked for me

Boarding experience was smooth. Flight attendants were friendly and helpful. Entertainment system on the Houston-Edmonton flight did not function for passengers on the left side of the aisle. On the bird's eye flight from Quito to Houston, they should not serve a meal. No one needs to eat after midnight and it is disturbing for those passengers trying to sleep.

it was so bad. I tried to board my flight from vancouver to saskatoon. And to my surprise they did not board me cause the flight was changed and no email was send to me. and on my boarding pass which i got from seattle says different flight. I did not knew anyone from Vancouver, air canada crew was rude, i asked for today flight but they were rude and i had early morning dental appointment in saskatoon. I was so much in pain and my whole day is wasted today. and i suffered alot. They did provide me hotel but they did not provide me any food. I am really really disappointed first time had so bad experience with air canada. I may think twice to book it again. If i can get any reply or any composition that would be great. Thanks

It was fine, definitely older planes with no charging or anything. There’s no entertainment set up on board, but it is nice that they allow you to access the in flight entertainment from your phone without having to pay for the Wi-Fi and they do offer free texting.

Terrible. Out flight was delayed for 21 (twenty one) hours. United is a joke.

Boarding was mayhem. Late boarding by 15 minutes because of lack of staff (missing 1 flight attendant. We had to wait for an arrival of another plane before we could board). Flight was a little rough, but cannot blame on airlines.

Impressed with the service despite turbulence because of the weather. Both flights arrived before their scheduled times.

Very comfortable (upgraded to business class). The audio on my screen didn’t work, but I managed to play the audio through my phone while watching the screen.

The food was the worst I’ve had on any flight I’ve ever been on.

Flight was full, and would have preferred an aisle seat, but due to getting a late ticket ,the seat I had was adequate. The flight crew were very help full and hard working. Food and drink were excellent for the 11hr flight. Overall I was pleased with flight, and would recommend British Airways again.

More choices on menu. Seemed only thing offered was Scottish, and while that’s good for the Scot’s it doesn’t help the Americans who don’t like that food. And I really hate it when, during sleep time the attendants have a very loud conversation right over you. Lastly, I paid 5000 dollars for business class, and having to pay more to choose my seat early is really an insult. Seems greedy

More choices on menu. Seemed only thing offered was Scottish, and while that’s good for the Scot’s it doesn’t help the Americans who don’t like that food. And I really hate it when, during sleep time the attendants have a very loud conversation right over you

The chicken adobo was a little too spicy but good otherwise. My personal opinion. Movie selection could be improved, too many horror movies. Could add a few more chick flicks! The flight was bumpy at times. We arrived a little early too! Flight attendants friendly.

Again flight was awesome except British Airways lost both gate checked luggage’s. Still missing

really bad they refused to check in luggages that I had purchased, even showing them the transaction receipt from british airways app the staff in miami was MEDIOCRE

Crew was great and responsive. Entertainment quit working with about 4 hours remaining on the flight. My seat cushion was broken.

Not very good , the stewardess were unfriendly and they don't like to be bothered. Cos was a night flight and they need to sleep.

British Airways staff are very polite and willing to help.

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.

Flight was delayed but the real issue is how long we sat after boarding. Space very limited for an overnight flight and seatbacks didn’t recline so it was almost impossible to sleep.

The staff made sure I was comfortable, moved me to a better seat with more leg room

Easy boarding and comfortable seating were plusses. Enjoyed the experience and good service from the captain and crew. Many thanks...!

Somehow, my booking was under my preferred name instead of my legal name so they almost didn’t let me board the plane at LAX. This problem should have been notified to me when I was still in Toronto.

Great overall. Quick boarding, attentive staff - great experience in premium class.

When arriving over 2 hours early to check k in at Charlotte airport I was told I would have to check my carry on ? Apparently the flight was full and may not be room. I was not given a choice and the agent was quite unpleasant about it. I am a senior amd was not comfortable me having to worry about my bag being lost vut it didn’t seem to bother him. There were lots and lots of people of all ages in line when we boarded with carryons and most larger than mine .the rest of my journey was pleasant vut this was totally unacceptable.

The layover was 6 PLUS hours and we were only given a $15.00 voucher. We missed our first activity in Quebec due to the delay.

Miserable staff as it was a late/delayed flight and crew wasn’t in the best spirits. Completely understood as neither was most of the passengers. Still unacceptable l.

Or the greatest and it ended up picking us up from Chicago to Toronto not sure who was tesponsible for the 4 hr delay. United should have been properly prepared for a scheduled flight from Austin to Chicago and they were not.

It was a short flight, and no entertainment. That was not a problem for us, but there is no option for "not applicable". There was a bit of turbulence, so there was no food service.

From boarding, to attention in flight, I couldn’t fault it.

Not having to check carry on bags when plane wasn’t full. (The told us it was)

I was in business class for the 8 hour flight where: 1. The WiFi did not work 2. The entertainment system did not work 3. We were told there were no hot drinks for the entire flight

I had an issue with the name on my ticket vs my passport name. I was very upset that the Iberia ticket clerk had no authorization to help me and I was left to fix it. It took 19 calls of persons promising to accomplish and not doing anything before I reached someone who helped me in 10 minutes. Two of them even hung up on me. I missed my original flight because of this. Terrible customer service.

The flight was delayed twice. When the crew explained about the debris causing flat tires, I was glad they took the time to change all four.

My carry-on bag was taken from me when I boarded. It was checked through to London at no charge. It took a big of shuffling, but I was glad not to need to mind it until baggage claim.

Flight boarded three hours late for no reason other than someone made a huge error in crew scheduling. We missed our connecting flight in Madrid and got zero help from American or Iberian airlines on rebooking. We had to pay for a car to take us to the Madrid train station and pay for train tickets to Santiago. We never used our booked flight to Santiago. American claims I can submit the expenses but they are not obligated to cover them. Very frustrating.

Flight delayed Service could be better Iberia staff are not really friendly

They cancelled the flight)(they said bad weather but many other flights took off) and made us wait 5 hours in line to figure out what to do. We ended up making a new flight the next day on another airlines...I hope they honor giving us our money back

Awful. The flight wasn't actually operated by Iberia, but by American Airlines. I was unable to get my boarding pass and as a result missed my connecting flight.

The payment system was not working so was unable to connect wifi the entire flight

everything to do with KAYAK was terrible. Your customer facing departments are utterly useless, timewasting and unhelpful.

I ordered short ribs for main course. It tasted sweet, really sweet. Horrible.

The screen didn’t work and I didn’t get the seat upgrade I paid $300 for. They were no help with that,

Paid $180 for seat selection, and selection essnt honored. Have to call for a refund.

My flights were great and the crew on them was lovely especially the London to Barcelona flight as Al & AJ were so amazingly nice. I wish they would be my crew always as they have the best customer service. Sadly both flights were delayed the first one from Vegas was because they clearly loaded the cargo wrong the plane was off balance making us 2 hours late. This made me miss my connection and sadly it was challenging rebooking while I was on the flight. I will never use Kayak again as there was no customer service number or live chat and you rebooked me on a flight 2 days later. I had my mom call BA to change it which she did after spending an hour on hold. This should not be so difficult. My second flight was an hour delayed due to not being able to disconnect the bridge from the plane but I did finally make it home.

The delay was not communicated via text and the person who helped with check in also didn’t inform me about the delay. I ended up missing my connection and it was a waste of 5 hours. The crew didn’t mention there would be someone at the gate informing of if I would be rebooked and there was no signage. Overall a very poor experience. The British Airways app was also very buggy, and didn’t work. I will avoid flying with British Airways when possible.

A little better than outward journey but mild chaos at the boarding gate because some people with boarding cards from connecting flights had cards which weren't recognised

The BA business class cabin is excellent,very comfortable for sleeping but the service could be improved.

Surly rude flight attendants. I ordered the chicken and was given a vegetarian meal with no explanation and no opportunity to change it. I tried to order another beverage and was told by the young humorless flight attendant to “wait”. And she never came back. The seats were very uncomfortable and cramped. The last time I flew British Airways was many years ago but I remember it was amazing and the crew were very charming. This was a terrible disappointment given the cost of the flight.

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

Information on your arrival and departure airports

Not what you’re looking for? Find thousands of other hotels, flights, car rentals and package deals with KAYAK.