STL - LHR

$315 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 9/14. 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

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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.
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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

Sun, Sep 14 - Tue, Sep 30
Air Canada Logo
1:30 pm - 9:35 amSTL-LHR
14h 05m1 stop
Air Canada Logo
6:50 am - 3:18 pmLHR-STL
14h 28m2 stops
$476Air Canada
Find Deal
Sun, Sep 14 - Tue, Sep 30
Air Canada Logo
1:30 pm - 9:35 amSTL-LHR
14h 05m1 stop
Air Canada Logo
12:05 pm - 7:38 pmLHR-STL
13h 33m1 stop
$489Air Canada
Find Deal
Mon, Nov 3 - Tue, Nov 11
United Airlines Logo
11:20 am - 10:15 amSTL-LHR
16h 55m1 stop
United Airlines Logo
1:25 pm - 2:25 pmLHR-STL
31h 00m2 stops
$507United Airlines
Find Deal
Tue, Oct 14 - Wed, Oct 22
United Airlines Logo
9:15 am - 6:35 amSTL-LHR
15h 20m1 stop
United Airlines Logo
2:05 pm - 10:49 amLHR-STL
26h 44m2 stops
$509United Airlines
Find Deal
Wed, Nov 19 - Fri, Dec 5
British Airways Logo
5:58 pm - 12:15 pmSTL-LHR
12h 17m1 stop
British Airways Logo
10:15 am - 6:15 pmLHR-STL
14h 00m1 stop
$510British Airways
Find Deal
Mon, Aug 18 - Wed, Aug 27
British Airways Logo
5:52 pm - 12:45 pmSTL-LHR
12h 53m1 stop
British Airways Logo
7:30 pm - 7:09 pmLHR-STL
29h 39m2 stops
$516British Airways
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Sun, Aug 24 - Fri, Sep 5
Delta Logo
9:17 am - 6:45 amSTL-LHR
15h 28m1 stop
Delta Logo
11:30 am - 11:23 pmLHR-STL
17h 53m2 stops
$523Delta
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Tue, Aug 19 - Tue, Aug 26
Delta Logo
11:02 am - 7:15 amSTL-LHR
14h 13m1 stop
Delta Logo
11:30 am - 10:02 pmLHR-STL
16h 32m2 stops
$524Delta
Find Deal
Wed, Aug 20 - Thu, Sep 4
Virgin Atlantic Logo
10:45 am - 6:45 amSTL-LHR
14h 00m2 stops
Virgin Atlantic Logo
10:55 am - 10:02 pmLHR-STL
17h 07m2 stops
$535Virgin Atlantic
Find Deal
Wed, Aug 20 - Sat, Aug 30
Virgin Atlantic Logo
10:45 am - 6:45 amSTL-LHR
14h 00m2 stops
Virgin Atlantic Logo
11:30 am - 9:55 pmLHR-STL
16h 25m2 stops
$576Virgin Atlantic
Find Deal
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 round-trip 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.

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 $1,272 and $1,172 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 3 weeks before departure, which saves you about 33% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 9 weeks before departure.

Good to know

Low seasonFebruary
Cheapest flight$315
Best time to beat the crowds with an average 4% drop in price.
Most popular time to fly with an average 5% 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 $315 for a one-way ticket and $476 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, oneworld, and SkyTeam 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 $976 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 $745 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.

Reviews of the 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 8896 reviews
8.1Crew
7.7Boarding
7.1Entertainment
7.3Comfort
6.6Food
Airline reviews

Terrible. Delayed 7 hours, and cancelled the flight, leaving me stranded and out of pocket $500 for an alternative last minute flight

2.0 MediocreV, Jul 2025MIA - EWR
Read more United Airlines reviews

Terrible. Delayed 7 hours, and cancelled the flight, leaving me stranded and out of pocket $500 for an alternative last minute flight

Was on time until within 1 hour of flight-how does that happen? Staff very friendly.

the delay for 3 hours was understandable due to weather conditions but the flight should’ve provided some on flight compensations or at least provide more food.

Weather delay in Chicago?. No sense of urgency to make connection in Chicago for our connecting flight that wasn't delayed. Connection was missed.

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.

I never flew. Flight was canceled. DIA worst airport in the country. Avoid at all costs.

I learned that seating towards the end of plane that a line forms for the restroom and people use your chair as a hand railing, bumping your seat consistently. I was seated in the aisle. I think that next time if I am towards the back row I would want to sit in the middle or window seat.

The best airline I have ever travel , really good customer service, attention and service !!

United could have one single once of customer service. No human United employee would help me with the invalid mileage plus number, they said I had to speak with the computer.

United sent me a mileage plus number last year but that number is invalid so I can’t use it to check into flights or collect mileage. There is human to speak about the problem, only computers who keep asking me if I am using the correct email. It’s so frustrating and I cannot resolve it.

Pathetic check in experience at JFK. Everything is self check in. Not enough staff present to help with when the check in process or the kiosk gets stuck. Staff present not welcoming or pleasant at all. On the other hand the NY based flight crew was great. Courteous and friendly throughout the flight. Special meals leave a lot to be desired. Kids meals should be made available when kids are flying and same goes for special kids meals too.

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

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.

Both flights are delayed so I rate the whole experience as mediocre.

I booked my flight months ago, and checked-in online about 12 hours before the flight. I received an email confirmation of check-in. I had no subsequent communication from Air Canada after my original booking. After arriving at the airport three hours before the flight, as instructed, I waited 90 minutes for an agent to appear to check my bag. I was informed that my flight had been canceled many weeks before, and that flight was no longer being run!! I showed a copy of my check-in confirmation, but no explanation could be found. I was placed on standby for the next flight and the connection. Luckily, those flights were not full and I arrived at my destination. I double checked my email, but I received no update about the flight from Air Canada until the day of the flight.

I had a good experience. I liked being informed about the status of my luggage

Very bad service the way back we was on the way for r two days very bad condition and waiting for luggage till now

I was forcefully re-routed to another destination and was delayed a total of 8hours. I have still not received my bags, no one is taking responsibility. The agents at the airport lied to me that I will get to my destination same time as my previous flight where I was forcefully re-routed from.

In flight entertainment system did not work across the whole plane for entire flight. Seats were very cramped. Cabin temperature was freezing cold. Crew was miserable and answered everyone in a short and barking manner. I’ve flown air Canada many many times and never had an issue. But this was unpleasant.

Flight was delayed by 1.5hrs. Once inside, people had their small handbags on the storage. The crew (male guy) was not helpful in making some space in the storage. Instead, he asked few bags to be checked-in and it was not a great experience. No attempt to help but just followed the things with a straight face. People had their literally small bags and he wouldnt not move from one storage to another even if there was space and would not let us do i as well. Once flight was on, they ran out of Orange juice, really running out of orange juice when the temp were 32.degrees outside. didnt made the sense. Onasking for a extra snack, he made a face as if he was giving me out of his pocket. if the flight was delayed, there could have an attempt to provide something extra incase people did asked.

Our flight was canceled at the last minute. Someone on the flight said the exact same thing happened to her the day before. I will say they helped us book a flight on another airline so that we could still make our vacation with little delay.

United had no (zero) record of our flight. It took over an hour of us standing in line with surly employee while others waited to get resolved. I have never experienced such poor service and poor empathy.

They screwed up so bad, I asked for a short check for my luggage since we had a 21 hour overnight layover in London at a hotel. They said I have to receive my luggage in London because it’s an overnight layover. Get to London, nope, my bags aren’t coming off they are staying in terminal 5 over night and going straight to Ibiza. So we had no luggage for a whole day and basically stuck with no clothes or washroom stuff. Finally get to Ibiza and my luggage is completely smashed and damaged and missing a wheel. Now I have to drag this 50 lbs luggage around Ibiza islands for 10 days. Wtf. So pissed off Air Canada is LITERALLY THE WORST AIRLINE IN THE WORLD

Check in needed to be in person, not nice. Also I won’t do connections in Charlotte again because you need to go through security again and short connections become a problem

Iberia lost my bag, said they found it in another country, said they sent it to me, but never did. Went my whole trip without my stuff, but expecting it to show up because that’s what they said would happen. Their communication sucks, their website sucks, and to top it all off, their seats are small and uncomfortable. They’re bad at their jobs and they should feel bad about themselves. Do not even get me started on the flight home. AVOID!

I described my experience in the previous window. I didn't realize that there would be another opportunity for this flight. Please look at my response in the previous window.

Boarding was 2 1/2 late no explanation Captain said he did not know why, but he rested at home for an extra couple of hours. Food was edible, Nothing more.

I liked the comfort of the plane. It was unexpected from past experiences.

BEWARE!!! Iberia changes your seats at random. I paid for a window seat and they changed it to one in the middle aisle resting against the bathroom- can’t lean back + hear every flush. This on a 11 hour flight.. There were families that were broken up with separate seats all over the plane. Lots of upset passengers showing their seat confirmation to the besieged and helpless airline steward. Also, the gluten free meal was tasteless.

Chair is very high. Your feet cannot touch the ground for 8 hours flight. It was a nightmare. Food was bad.

ground crew and check-in was pathetic - insisted on charging me for luggage even though the ticket said it was already included. They also accidentally sent my luggage through without a luggage tag and had to retrieve it. Generally, it was like a bad movie.

Moved the flight an hour later, were not reliable about confirmation, website didn't work, no gate information, boarding was a mad house. Flight itself was fine and short. Organization needs work.

The app on phone and the online check in is not good, it would not give me the option of Spain or Madrid City in the drop down menu and I couldn't move forward with online check in.

Flight was delayed. Though I checked in with BA live chat three times, our special meals were not provided.

My experience with British Airways is excellent, thanks for all 🫶🏻✈️

The crew is very friendly and helpful. The food is good for airplane food. The flight is long and hard to sleep. The leg space is great. The plane arrived in plenty of time.

Enjoyable flight, helpful crew everything was organized to accommodate passengers.

Captain sick. Unable to get replacement so delayed me 30 hours, many others delayed 54 hours. TOTALLY DESTROYED ALL MY PLANS, including lost my rental car which would now cost over 5 times what I paid so stuck with buses n trains... lost hotel reservations.... HORRIBLE!!!

They’ve lost my bag and I have no way of really getting in touch with anyone and have received no updates.

Very crowded, no real explanation of food "chicken or pasta?" After dinner no drinks service. Plane was clean, but little help with finding soaces fir luggage to get into overhead bins. Many passengers putting 2 bags, hats, duty free in overhead bins so no space for roll ons

Flight was good but seat in 12D was not comfortable, better on the Airbus 321 from Tampa to Charlotte. No breakfast was served before landing in zLonfon only a coffee and orange juice.

I was transferred to an American Airlines flight. The boarding was late and unorganized. The seating was extremely tight and uncomfortable. Will not use AA again.

The entertainment selection was ok, but overall not bad! The crew was great.

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