AirHint found the following cheapest return flights from Seattle (SEA) to Frankfurt (FRA) in September 2025 (see full year).

Return flights

16 Sep - 23 Sep	Condor
17 Sep - 24 Sep	Condor
10 Sep - 23 Sep	Condor
16 Sep - 30 Sep	Condor
08 Sep - 24 Sep	Condor
25 Sep - 09 Oct	Condor	direct
30 Sep - 07 Oct	Condor
28 Sep - 13 Oct	Condor	direct
03 Sep - 24 Sep	Condor
29 Sep - 25 Oct	Condor	direct
08 Sep - 15 Sep	Condor	direct
05 Sep - 09 Oct	Condor
10 Sep - 22 Sep	Condor
18 Sep - 02 Oct	Condor
30 Sep - 07 Oct	Condor	direct
13 Sep - 26 Sep	Condor
11 Sep - 04 Oct	Condor
13 Sep - 04 Oct	Condor
08 Sep - 24 Sep	Condor	direct
02 Sep - 06 Oct	Icelandair

Also check the deals for one-way flights from Seattle to Frankfurt 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.

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Cheapest return flights from Seattle to Frankfurt in September from 440€

Return flights