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Cheap flights from St. Louis to London Heathrow Airport from £259

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 9/4. Fares are subject to change and may not be available on all flights or dates of travel.
STL — LHR
27 12月 — 3 1月1
1 adult
1 adult, Economy, 0 bags

Cheapflights Tip: The best prices from Lambert-St Louis to London Heathrow are usually found in October or November, booked 27 days in advance, depart on a Wednesday or Friday and return on a Saturday

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Cheapest flights from St. Louis to Heathrow
Explore the most affordable flight options available from St. Louis to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 27 11月 2025.

週二 2/1214:38STL - LHR
1 stop12h 07mKLM
週五 12/1213:00LHR - STL
1 stop13h 47mKLM
Deal found 26/11£496
週三 3/1216:05STL - LHR
1 stop13h 15mAir Canada
週五 12/1213:25LHR - STL
2 stops15h 20mAir Canada
Deal found 26/11£498
週二 2/1211:50STL - LHR
1 stop16h 35mLufthansa
週日 7/1207:30LHR - STL
2 stops20h 10mLufthansa
Deal found 26/11£507
週二 2/1212:55STL - LHR
1 stop11h 45mUnited Airlines
週日 7/1206:50LHR - STL
2 stops18h 27mUnited Airlines
Deal found 24/11£512
週日 30/1116:05STL - LHR
2 stops22h 30mUnited Airlines
週日 7/1206:50LHR - STL
2 stops18h 27mUnited Airlines
Deal found 25/11£514
週三 3/1209:30STL - LHR
2 stops17h 15mDelta
週一 8/1210:00LHR - STL
2 stops16h 47mDelta
Deal found 25/11£517
週二 30/1209:55STL - LHR
2 stops14h 45mUnited Airlines
週五 9/112:05LHR - STL
2 stops15h 08mUnited Airlines
Deal found 26/11£520
週四 27/1116:05STL - LHR
1 stop10h 25mMultiple Airlines
週四 4/1211:30LHR - STL
1 stop32h 25mMultiple Airlines
Deal found 26/11£521
週日 30/1112:49STL - LHR
1 stop12h 16mKLM
週日 7/1210:45LHR - STL
1 stop14h 25mKLM
Deal found 26/11£534
週二 30/1218:35STL - LHR
2 stops30h 35mAir Canada
週三 7/113:00LHR - STL
2 stops34h 43mAir Canada
Deal found 25/11£539

Cheap flight deals from St. Louis to Heathrow

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Heathrow (LHR). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 27 11月 2025.

Round-trip from

£496

One-way from

£259

Popular in

June

Cheapest in

October

Average price

£569

Good round-trip deal

£814 or less
Lufthansa
  • Lufthansa
  • 12/3-17/3
  • 4 total stops
  • 35h 18m total
  • St. Louis to London
Search Deals
9/4
  • 9/4
  • 3 total stops
  • 40h 58m total
  • St. Louis to London
Search Deals
Highest demand for flights based on searches. 17% potential increase in price (£110 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (£19 potential savings vs. average return price).
Search Deals
Average for round-trip flights in November 2025
Search Deals
Price to beat on a round-trip flight from Lambert-St Louis to London Heathrow.
Search Deals

Cheapflights Fare Finder

 
Customise your flight search to find flights from St. Louis to Heathrow that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 858,174 searches. Data last updated 27 11月 2025.
Use the filters below to find and compare flights from St. Louis to London Heathrow Airport that are best for you.

Fly from

St. Louis

Fly to

Heathrow

Route

Depart

Return

Price

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

週三 4/2

16:05-08:30

1 stop10h 25m

London Heathrow

週日 8/2

13:25-22:58

2 stops15h 33m

£497

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

週五 17/4

06:00-06:30

1 stop18h 30m

London Heathrow

週四 23/4

08:40-20:31

2 stops17h 51m

£501

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

週五 27/3

16:05-20:35

2 stops23h 30m

London Heathrow

週二 31/3

09:30-11:09

2 stops31h 39m

£501

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

週三 22/4

12:10-13:10

1 stop19h 00m

London Heathrow

週一 27/4

06:30-16:45

2 stops16h 15m

£501

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

週日 12/4

15:25-13:10

1 stop15h 45m

London Heathrow

週日 26/4

06:30-16:45

2 stops16h 15m

£501

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

週四 30/4

19:05-13:30

1 stop12h 25m

London Heathrow

週三 6/5

06:30-16:49

2 stops16h 19m

£501

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

週四 15/1

11:55-06:50

1 stop12h 55m

London Heathrow

週一 26/1

12:35-21:15

1 stop14h 40m

£510

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

週四 15/1

06:00-07:30

1 stop19h 30m

London Heathrow

週一 26/1

06:50-22:58

2 stops22h 08m

£512

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

週四 15/1

12:44-10:45

2 stops16h 01m

London Heathrow

週一 26/1

11:10-22:58

2 stops17h 48m

£513

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

週二 10/3

15:26-07:55

1 stop11h 29m

London Heathrow

週一 16/3

09:00-21:00

2 stops17h 00m

£518

Flights are sorted by cheapest return flights first.

Deals found on 26/11

Showing 1-10 of 23 results
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2
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Best time to book a flight from St. Louis to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow from St. Louis with our price prediction graph.
Estimated return price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from St. Louis to London Heathrow Airport

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

Use this chart to determine the optimal time to book a return flight from St. Louis to Heathrow. Price data was last updated on 21 November 2025.

The best time to book flights from St. Louis to London Heathrow Airport is 27 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

What is the cheapest month to book a flight from St. Louis to London Heathrow Airport?

Currently, September is the cheapest month in which you can book a flight from St. Louis to London Heathrow Airport (average of £401). Flying from St. Louis to London Heathrow Airport in June is currently the most expensive (average of £758). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from STL to LHR?

Find hourly flight availability from St. Louis to Heathrow. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 27 11月 2025.

Unlike in the afternoon, when flights are generally more expensive, you can save up to 19% on flights from St. Louis to London Heathrow Airport by exploring options for tickets in the morning.

Reviews of airlines servicing Heathrow

Get insights into the airlines that provide service to Heathrow. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Heathrow. Reviews last updated 27 11月 2025.
See what other customers who have flown with KLM, Virgin Atlantic, andAir Canada from St. Louis to London Heathrow Airport have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
KLM
7.7
Good
1,423 reviews
Check prices

Crew

8.4

Overall

7.7

Boarding

7.8

Comfort

7.6

Food

7.2

Entertainment

7.1

Reviews

1 / 20
2.0
Mediocre

Abisola,Oct 2025

LOS - CDG

The food option was finished and what wa left was vegan pasta so I had to go without food for an 8 hour flight without any sort of empathy from crew that was mean.
KLM
7.7
Good
1,423 reviews
KLM
7.7
Good
1,423 reviews
Check prices

Crew

8.4

Overall

7.7

Boarding

7.8

Comfort

7.6

Food

7.2

Entertainment

7.1

Reviews

1 / 20
2.0
Mediocre

Abisola,Oct 2025

LOS - CDG

The food option was finished and what wa left was vegan pasta so I had to go without food for an 8 hour flight without any sort of empathy from crew that was mean.
Virgin Atlantic
7.5
Good
675 reviews
KLM
7.7
Good
1,423 reviews
Check prices

Crew

8.4

Overall

7.7

Boarding

7.8

Comfort

7.6

Food

7.2

Entertainment

7.1

Reviews

1 / 20
2.0
Mediocre

Abisola,Oct 2025

LOS - CDG

The food option was finished and what wa left was vegan pasta so I had to go without food for an 8 hour flight without any sort of empathy from crew that was mean.
Air Canada
7.1
Good
10,481 reviews
KLM
7.7
Good
1,423 reviews
Check prices

Crew

8.4

Overall

7.7

Boarding

7.8

Comfort

7.6

Food

7.2

Entertainment

7.1

Reviews

1 / 20
2.0
Mediocre

Abisola,Oct 2025

LOS - CDG

The food option was finished and what wa left was vegan pasta so I had to go without food for an 8 hour flight without any sort of empathy from crew that was mean.
British Airways
6.7
Okay
7,539 reviews
KLM
7.7
Good
1,423 reviews
Check prices

Crew

8.4

Overall

7.7

Boarding

7.8

Comfort

7.6

Food

7.2

Entertainment

7.1

Reviews

1 / 20
2.0
Mediocre

Abisola,Oct 2025

LOS - CDG

The food option was finished and what wa left was vegan pasta so I had to go without food for an 8 hour flight without any sort of empathy from crew that was mean.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Heathrow. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from St. Louis to London Heathrow?

    Lambert-St Louis (STL) is the airport you will fly out of if you book a flight from St. Louis to London Heathrow. You should not have trouble finding flights to London Heathrow from Lambert-St Louis; the airport handles an average of 0 outbound flights to London Heathrow per day. You should also have plenty of airline options to choose from since 4 airlines have flights from the St. Louis airport to London Heathrow. It is only a 12.7 mi journey to Lambert-St Louis (STL) from St. Louis’s city center.

  • How long is the flight from St. Louis to London Heathrow Airport?

    For as low as £497, Air Canada can have you in London Heathrow Airport from St. Louis in 10h 25m. There are 4186 mi between St. Louis and London Heathrow Airport. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

  • What are the cheapest airlines flying from St. Louis to London Heathrow Airport round-trip?

    KLM, at £373, was found to be the cheapest airline from St. Louis to London Heathrow Airport.Alternate airlines flying return to your destination include British Airways and Air Canada. You may be able to fly from St. Louis to London Heathrow Airport for 45% less than the average price by searching for these airlines.

  • What are the cheapest airlines to fly from St. Louis to London Heathrow Airport one-way?

    The cheapest airline one-way is Iberia, with whom users have recently found tickets for as low as £276. However, be on the lookout for offers from Austrian Airlines and Delta, as they are both options that can get you from St. Louis to London Heathrow Airport for a low price.

  • What are the cheapest flights from St. Louis to London Heathrow Airport?

    The cheapest flight price from St. Louis to London Heathrow Airport is £814. On average you can expect to pay £852. The most popular route, (Lambert-St Louis - London Heathrow), can usually be booked for £431.

  • Can I find deals for flights from St. Louis to Heathrow that include hotel bookings?

    Yes. In addition to deals on St. Louis to Heathrow flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from St. Louis to Heathrow?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Heathrow.

  • Can I find deals for business class flights from St. Louis to Heathrow?

    Yes. Cheapflights offers flight deals from St. Louis to Heathrow by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

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

    Currently, September is the cheapest month in which you can book a flight from St. Louis to London Heathrow Airport (average of £401). Flying from St. Louis to London Heathrow Airport in June is currently the most expensive (average of £758). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Travelling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Milton Keynes
Slough
Croydon
Hounslow
Northampton
Gatwick
Luton
Ilford
Wembley
Deal
Hayes
Colchester
Watford
Brentford
Winchester
Swindon
Crawley
Romford
Chichester
Bedford

Browse thousands of different options on Cheapflights for your next trip

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Top 4 airlines flying from St. Louis to Heathrow

Discover the top 4 airlines that operate flights from St. Louis to Heathrow. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 858,174 searches. Data last updated 27 11月 2025.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest£373Average£630FlexibilityNo cancel feeOn-time75%
Search KLM flights
British AirwaysCheapest£439Average£685FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Air CanadaCheapest£443Average£671FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
Virgin AtlanticCheapest£478Average£646FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights

Fly with Cheapflights

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How does Cheapflights help users find flights from St. Louis to Heathrow?

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Why should you use Cheapflights to find cheap flight tickets from St. Louis to Heathrow?

It’s simple! Cheapflights, which is free to use for everyone, saves millions of users time and money every year by helping them find the cheapest and most suitable flights from St. Louis to Heathrow.

Can Cheapflights find flights from St. Louis to Heathrow with no change fees?

Yes! Cheapflights helps users easily find flights from St. Louis to Heathrow with no change fees.

Can Cheapflights notify me if prices for flights from St. Louis to Heathrow become cheaper?

Not ready to book yet? You can track prices for flights from St. Louis to Heathrow on Cheapflights with our Price Alert feature and get notified when better prices are available.

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