Cheap flights from London Heathrow Airport to St. Louis from £345

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 5/5. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — STL
27 Apr — 4 May1
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 72 days in advance, depart on a Thursday or Tuesday and return on a Wednesday

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 28 March 2026.

Mon 20/412:15
LHR
-
STL
1 stop16h 02m
Finnair
Thu 30/412:27
STL
-
LHR
1 stop19h 58m
Finnair
Deal found 23/3£592
Wed 2/916:35
LHR
-
STL
2 stops22h 39m
Finnair
Wed 23/912:47
STL
-
LHR
1 stop12h 08m
Finnair
Deal found 23/3£594
Mon 4/516:55
LHR
-
STL
1 stop22h 49m
Finnair
Mon 11/511:25
STL
-
LHR
2 stops14h 35m
Finnair
Deal found 24/3£595
Wed 22/418:05
LHR
-
STL
2 stops29h 07m
Finnair
Wed 29/418:11
STL
-
LHR
1 stop14h 14m
Finnair
Deal found 25/3£596
Tue 21/416:25
LHR
-
STL
Nonstop9h 05m
Multiple Airlines
Tue 28/418:11
STL
-
LHR
1 stop11h 59m
Multiple Airlines
Deal found 24/3£603
Wed 2/916:25
LHR
-
STL
Nonstop9h 05m
Multiple Airlines
Wed 23/915:33
STL
-
LHR
1 stop15h 17m
Multiple Airlines
Deal found 25/3£604
Wed 22/416:25
LHR
-
STL
Nonstop9h 05m
British Airways
Wed 29/421:35
STL
-
LHR
Nonstop8h 00m
British Airways
Deal found 25/3£606
Wed 9/916:25
LHR
-
STL
Nonstop9h 05m
American Airlines
Wed 16/915:33
STL
-
LHR
1 stop15h 17m
American Airlines
Deal found 24/3£616

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 28 March 2026.

Round-trip from

£592

One-way from

£345

Popular in

July

Cheapest in

February

Average price

£707

Good round-trip deal

£737 or less

Good one-way deal

£1,839 or less
Finnair
  • Finnair
  • 20/4-30/4
  • 2 total stops
  • 36h 00m total
  • London to St. Louis
5/5
  • 5/5
  • 3 total stops
  • 50h 04m total
  • London to St. Louis
Highest demand for flights based on searches. 7% potential increase in price (£45 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 March 2026
Price to beat on a round-trip flight from London Heathrow to Lambert-St Louis.
Price to beat on a one-way 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 28 March 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

Cheapest return flight

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Mon 4/5

06:30-16:42

2 stops16h 12m

Lambert-St Louis

Mon 18/5

06:45-07:10

1 stop18h 25m

£635

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Wed 2/9

09:55-20:31

2 stops16h 36m

Lambert-St Louis

Wed 23/9

19:05-14:35

2 stops13h 30m

£637

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Mon 11/5

09:55-21:09

2 stops17h 14m

Lambert-St Louis

Mon 18/5

06:00-07:15

1 stop19h 15m

£655
Fastest return journey

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Thu 10/9

11:00-22:00

1 stop17h 00m

Lambert-St Louis

Mon 14/9

16:47-09:25

1 stop10h 38m

£661

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Sat 2/5

15:15-23:36

1 stop14h 21m

Lambert-St Louis

Sun 10/5

16:25-14:35

1 stop16h 10m

£679

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Sun 10/5

10:45-21:09

1 stop16h 24m

Lambert-St Louis

Sun 17/5

19:01-14:35

2 stops13h 34m

£681

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Thu 10/9

06:40-23:37

2 stops22h 57m

Lambert-St Louis

Mon 14/9

15:42-16:00

2 stops18h 18m

£709
Cheapest one-way

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Mon 18/5

14:10-22:45

1 stop14h 35m

£388

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Tue 5/5

19:30-13:25

1 stop23h 55m

£398
Fastest single journey

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Fri 15/5

06:30-13:25

1 stop12h 55m

£434

Flights are sorted by cheapest return flights first.

Deals found on 27/3

Showing 1-10 of 17 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 13 March 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 72 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 £409). Flying from London Heathrow Airport to St. Louis in December is currently the most expensive (average of £628). 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 28 March 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.

Comfort

7.5

Food

6.7

Overall

7.7

Entertainment

6.9

Crew

8.2

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

Comfort

7.5

Food

6.7

Overall

7.7

Entertainment

6.9

Crew

8.2

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

Comfort

7.5

Food

6.7

Overall

7.7

Entertainment

6.9

Crew

8.2

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

Comfort

7.5

Food

6.7

Overall

7.7

Entertainment

6.9

Crew

8.2

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

Comfort

7.5

Food

6.7

Overall

7.7

Entertainment

6.9

Crew

8.2

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

Comfort

7.5

Food

6.7

Overall

7.7

Entertainment

6.9

Crew

8.2

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 16h 12m. 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 £175. Other airlines that can offer you cheap pricing are United Airlines, from £477, and British Airways, from £482. 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 £345. Users have also found prices from £361 and £365 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 £1,397, our data shows the cheapest flight currently is £586. When looking at the most popular route, (London Heathrow - Lambert-St Louis), you can expect to pay £604 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 £409). Flying from London Heathrow Airport to St. Louis in December is currently the most expensive (average of £628). 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 28 March 2026.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest£175Average£772FlexibilityNo cancel feeOn-time71%
Search American Airlines flights
United AirlinesCheapest£477Average£742FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
British AirwaysCheapest£482Average£762FlexibilityNo cancel feeOn-time70%
Search British Airways flights
KLMCheapest£524Average£832FlexibilityNo cancel feeOn-time75%
Search KLM flights
Virgin AtlanticCheapest£560Average£782FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
FinnairCheapest£601Average£703FlexibilityNo cancel feeOn-time76%
Search Finnair flights
Air CanadaCheapest£608Average£737FlexibilityNo cancel feeOn-time67%
Search Air Canada flights
IberiaCheapest£662Average£727FlexibilityNo cancel feeOn-time77%
Search Iberia flights
LufthansaCheapest£665Average£808FlexibilityNo 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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