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

Return flights

13 May - 20 May	Air Canada
08 May - 12 May	Air Canada
01 May - 05 May	Air Canada
01 May - 08 May	Air Canada
07 May - 11 May	Iberia
08 May - 11 May	Iberia
08 May - 12 May	American Airlines	direct
01 May - 05 May	American Airlines	direct
13 May - 27 May	Air Canada
12 May - 02 Jun	Air Canada
12 May - 02 Jun	British Airways	direct
19 May - 03 Jun	Air Canada
13 May - 27 May	British Airways	direct
27 May - 11 Jun	Air Canada
31 May - 30 Jun	Aer Lingus
31 May - 30 Jun	British Airways	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 $646

Return flights