Cheap flights from London Heathrow Airport to St. Louis from £336

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 24/4. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — STL
29 Mar — 5 Apr1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from London Heathrow to Lambert-St Louis are usually found in February or March, booked 89 days in advance, depart on a Thursday or Friday and return on a Monday

Cheap flight deals from Heathrow to St. Louis

Enter your travel dates to find the best prices.

Cheapest flights from Heathrow to St. Louis
Explore the most affordable flight options available from Heathrow to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 27 February 2026.

Tue 1/916:25
LHR
-
STL
Nonstop9h 05m
Finnair
Tue 8/920:00
STL
-
LHR
1 stop10h 15m
Finnair
Deal found 24/2£524
Mon 20/409:45
LHR
-
STL
1 stop12h 15m
Finnair
Thu 30/409:10
STL
-
LHR
1 stop15h 45m
Finnair
Deal found 25/2£527
Wed 2/910:05
LHR
-
STL
2 stops16h 14m
Finnair
Wed 23/918:55
STL
-
LHR
2 stops20h 45m
Finnair
Deal found 24/2£528
Tue 1/916:25
LHR
-
STL
Nonstop9h 05m
Multiple Airlines
Tue 8/909:08
STL
-
LHR
1 stop15h 47m
Multiple Airlines
Deal found 24/2£529
Wed 2/916:25
LHR
-
STL
Nonstop9h 05m
British Airways
Wed 23/912:47
STL
-
LHR
1 stop12h 08m
British Airways
Deal found 24/2£536
Mon 20/406:15
LHR
-
STL
2 stops19h 14m
British Airways
Thu 30/414:12
STL
-
LHR
1 stop12h 53m
British Airways
Deal found 24/2£549
Fri 1/516:25
LHR
-
STL
Nonstop9h 05m
Finnair
Wed 6/511:06
STL
-
LHR
1 stop17h 59m
Finnair
Deal found 26/2£554
Sun 19/419:00
LHR
-
STL
2 stops30h 29m
British Airways
Sun 3/520:03
STL
-
LHR
1 stop28h 47m
British Airways
Deal found 23/2£555
Thu 30/414:45
LHR
-
STL
1 stop13h 32m
Finnair
Thu 7/511:06
STL
-
LHR
1 stop15h 54m
Finnair
Deal found 24/2£556

Find flight deals from Heathrow to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Heathrow (LHR) to St. Louis (STL). 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 February 2026.

Round-trip from

£527

One-way from

£336

Popular in

July

Cheapest in

February

Average price

£542

Good round-trip deal

£560 or less
Finnair
  • Finnair
  • 20/4-30/4
  • 3 total stops
  • 31h 40m total
  • London to St. Louis
24/4
  • 24/4
  • 3 total stops
  • 42h 34m total
  • London to St. Louis
Highest demand for flights based on searches. 9% potential increase in price (£53 potential increase over avg. return price).
Cheapest flight prices on average. 1% potential price decrease (£9 potential savings vs. average return price).
Average for round-trip flights in February 2026
Price to beat on a round-trip flight from London Heathrow to Lambert-St Louis.

Cheapflights Fare Finder

 
Customise your flight search to find flights from Heathrow to St. Louis 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 February 2026.
Use the filters below to find and compare flights from London Heathrow Airport to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Tue 21/4

15:15-22:19

1 stop13h 04m

Lambert-St Louis

Tue 28/4

14:33-06:50

1 stop10h 17m

£559

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Sun 12/4

12:25-23:31

1 stop17h 06m

Lambert-St Louis

Sun 19/4

09:26-07:10

2 stops15h 44m

£634

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Fri 21/8

11:30-23:01

2 stops17h 31m

Lambert-St Louis

Thu 17/12

09:00-06:25

1 stop15h 25m

£657

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Thu 28/5

14:45-23:54

1 stop15h 09m

Lambert-St Louis

Tue 9/6

19:51-18:55

1 stop17h 04m

£708

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Thu 28/5

06:30-16:46

2 stops16h 16m

Lambert-St Louis

Sun 7/6

17:00-14:35

1 stop15h 35m

£712

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Fri 29/5

06:30-17:05

2 stops16h 35m

Lambert-St Louis

Mon 8/6

11:51-07:15

2 stops13h 24m

£712

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Wed 1/7

16:25-19:30

Nonstop9h 05m

Lambert-St Louis

Sun 5/7

19:50-08:05

1 stop30h 15m

£715

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Thu 30/4

07:05-23:36

3 stops22h 31m

Lambert-St Louis

Thu 7/5

13:27-18:30

2 stops23h 03m

£770

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Mon 20/4

06:15-19:33

2 stops19h 18m

£353

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Mon 29/6

19:30-13:25

1 stop23h 55m

£440

Flights are sorted by cheapest return flights first.

Deals found on 24/2

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

Best time to book a flight from Heathrow to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Heathrow 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 London Heathrow Airport to St. Louis

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

Use this chart to determine the optimal time to book a return flight from Heathrow to St. Louis. Price data was last updated on 20 February 2026.

To ensure you get the cheapest price possible for a flight from London Heathrow Airport to St. Louis, you should look to book at least 89 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

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

Currently, September is the cheapest month in which you can book a flight from London Heathrow Airport to St. Louis (average of £403). Flying from London Heathrow Airport to St. Louis in December is currently the most expensive (average of £624). 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.

How much does it cost for a return flight from London Heathrow Airport to St. Louis?

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. 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 St. Louis. Reviews last updated 27 February 2026.
Get a feel of what it's like to fly with Finnair, United Airlines, andAir Canada from London Heathrow Airport to St. Louis by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Food

6.7

Crew

8.2

Entertainment

6.9

Comfort

7.4

Overall

7.6

Boarding

7.7

Reviews

1 / 20
2.0
Mediocre

Vlad-Valentin,Jan 2026

LHR - YVR

baggage allowance was different between the outgoing and inbound flights

Food

6.7

Crew

8.2

Entertainment

6.9

Comfort

7.4

Overall

7.6

Boarding

7.7

Reviews

1 / 20
2.0
Mediocre

Vlad-Valentin,Jan 2026

LHR - YVR

baggage allowance was different between the outgoing and inbound flights

Food

6.7

Crew

8.2

Entertainment

6.9

Comfort

7.4

Overall

7.6

Boarding

7.7

Reviews

1 / 20
2.0
Mediocre

Vlad-Valentin,Jan 2026

LHR - YVR

baggage allowance was different between the outgoing and inbound flights

Food

6.7

Crew

8.2

Entertainment

6.9

Comfort

7.4

Overall

7.6

Boarding

7.7

Reviews

1 / 20
2.0
Mediocre

Vlad-Valentin,Jan 2026

LHR - YVR

baggage allowance was different between the outgoing and inbound flights

Food

6.7

Crew

8.2

Entertainment

6.9

Comfort

7.4

Overall

7.6

Boarding

7.7

Reviews

1 / 20
2.0
Mediocre

Vlad-Valentin,Jan 2026

LHR - YVR

baggage allowance was different between the outgoing and inbound flights

Food

6.7

Crew

8.2

Entertainment

6.9

Comfort

7.4

Overall

7.6

Boarding

7.7

Reviews

1 / 20
2.0
Mediocre

Vlad-Valentin,Jan 2026

LHR - YVR

baggage allowance was different between the outgoing and inbound flights

Related info for your journey

Find useful and relevant information for your journey from Heathrow to St. Louis. 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 into for flights to St. Louis from London Heathrow?

    For a flight from London Heathrow to St. Louis, you will be flying into Lambert-St Louis. Lambert-St Louis (STL) is just 12.7 mi from the center of the city. Lambert-St Louis is the only St. Louis airport and it handles 0 inbound flights from London Heathrow per day. 9 airlines have flights to Lambert-St Louis from London Heathrow on a regular basis.

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

    Departing from London Heathrow Airport to St. Louis will take you 13h 04m. London Heathrow Airport and St. Louis are separated by a distance of 4186 mi. This flight may include one or multiple stops.

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

    Cheapflights users have booked flights from London Heathrow Airport to St. Louis round-trip from £169. Other airlines that can offer you cheap pricing are United Airlines, from £469, and British Airways, from £474. American Airlines is priced at 76% lower than the current average price of a flight leaving 3 months from now.

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

    For one-way options, check prices for British Airways. According to our data, you can fly for as low as £340. Users have also found prices from £355 and £359 on United Airlines and Finnair, respectively.

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

    While on average a flight from London Heathrow Airport to St. Louis is generally £673, our data shows the cheapest flight currently is £536. When looking at the most popular route, (London Heathrow - Lambert-St Louis), you can expect to pay £554 for that flight.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Heathrow to St. Louis 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 London Heathrow Airport to St. Louis?

    Currently, September is the cheapest month in which you can book a flight from London Heathrow Airport to St. Louis (average of £403). Flying from London Heathrow Airport to St. Louis in December is currently the most expensive (average of £624). 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

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Top 9 airlines flying from Heathrow to St. Louis

Discover the top 9 airlines that operate flights from Heathrow to St. Louis. 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 February 2026.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest£169Average£760FlexibilityNo cancel feeOn-time71%
Search American Airlines flights
United AirlinesCheapest£469Average£729FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
British AirwaysCheapest£474Average£742FlexibilityNo cancel feeOn-time70%
Search British Airways flights
FinnairCheapest£505Average£661FlexibilityNo cancel feeOn-time76%
Search Finnair flights
KLMCheapest£515Average£794FlexibilityNo cancel feeOn-time75%
Search KLM flights
Virgin AtlanticCheapest£551Average£772FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
Air CanadaCheapest£598Average£733FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
IberiaCheapest£651Average£722FlexibilityNo cancel feeOn-time77%
Search Iberia flights
LufthansaCheapest£654Average£795FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

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

Cheapflights makes it easy to find Heathrow to St. Louis flights by helping our users search from 900+ travel sites for deals. We also provide you with filters for cabin, price, airline, airports, number of stops, and many more to narrow down that perfect flight.

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

By finding flights from multiple airlines and providers at completely no cost, Cheapflights helps millions of users like you annually find the best flights to St. Louis from Heathrow.

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

Certainly. Search results for flights to St. Louis from Heathrow shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

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

Yes, Cheapflights offers price alerts on Heathrow to St. Louis flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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