Cheap flights from London to St. Louis from $425

In general, August is the cheapest month to fly from London to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $91. The month of September is another great option to travel to St. Louis, with average flight prices from London averaging around $170.

The cheapest day to depart on your flight to St. Louis is on a Sunday when prices can be found for as low as $1,100. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Friday because tickets tend to average around $1,408. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

Fly from London Heathrow to Lambert-St Louis for the best London - Lambert-St Louis flight prices

You are more likely to see cheaper flights to St. Louis from London when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $1,011 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from London for as low as $853 on momondo.

There is only 1 cabin class available to choose from on London to St. Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

You could potentially save up to 14% on your flight if you consider stops on a London to St. Louis flight.

Historically, on average around 15% of flights between London and St. Louis have experienced a delay on any given week. The average delay length over the past 12 months has been 117 minutes.

Generally, flights departing in the early afternoon tend to experience fewer delays. Flights in the early afternoon have, in the past, seen delays more frequently in comparison.

Friday is statistically the day of the week which experiences the fewest number of delays on this flight route. Wednesday has historically seen more delays on average compared to the rest of the week.

According to our data, British Airways have had the least number of delays on this route over the last 12 months; with about 15% of their flights experiencing any sort of delay.

The number of flights available between London and St. Louis is 2 per day as of July 2026. The most frequent departure time is 4:00PM, with 100% of daily flights leaving in the afternoon.

As of July 2026, 20 flights take off from London and land in St. Louis each week. The most common flight departure day for this route is Tue, with 25% of weekly flights taking off on this day.