AirHint found the following cheapest return flights from St. Louis (STL) to London (LHR) in May 2026 (see full year).

Return flights

01 May - 08 May	Air Canada
03 May - 10 May	Air Canada
02 May - 09 May	Air Canada
13 May - 27 May	Air Canada
13 May - 29 May	Air Canada
01 May - 08 May	American Airlines	direct
03 May - 10 May	American Airlines	direct
13 May - 27 May	American Airlines	direct
07 May - 14 May	British Airways
17 May - 06 Jun	Air Canada
17 May - 24 May	British Airways	direct
21 May - 13 Jun	Air Canada
27 May - 11 Jun	Air Canada
27 May - 03 Jun	British Airways
22 May - 13 Jun	Air Canada
31 May - 30 Jun	Air Canada
31 May - 30 Jun	American Airlines	direct

Also check the deals for one-way flights from St. Louis to London in May.

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

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Cheapest return flights from St. Louis to London in May from $684

Return flights