AirHint found the following cheapest return flights from London (LON) to Washington (IAD)
in September 2025 (see full year ).
Return flights
10 Sep
- 15 Sep
British Airways
590 €
02 Sep
- 09 Sep
British Airways
601 €
04 Sep
- 07 Sep
British Airways
602 €
15 Sep
- 29 Sep
Icelandair
607 €
09 Sep
- 17 Sep
Icelandair
624 €
17 Sep
- 24 Sep
Icelandair
626 €
19 Sep
- 22 Sep
Icelandair
645 €
06 Sep
- 23 Sep
Scandinavian Airlines
646 €
06 Sep
- 27 Sep
Scandinavian Airlines
647 €
13 Sep
- 21 Sep
Scandinavian Airlines
647 €
27 Sep
- 06 Oct
Icelandair
647 €
19 Sep
- 05 Oct
Icelandair
676 €
28 Sep
- 13 Oct
Icelandair
685 €
25 Sep
- 10 Oct
Icelandair
719 €
27 Sep
- 06 Oct
British Airways
751 €
direct
29 Sep
- 05 Oct
Scandinavian Airlines
781 €
19 Sep
- 05 Oct
British Airways
819 €
direct
29 Sep
- 05 Oct
British Airways
830 €
direct
28 Sep
- 13 Oct
British Airways
848 €
direct
25 Sep
- 10 Oct
British Airways
884 €
direct
Also check the deals for one-way flights from London to Washington in September .
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.