AirHint found the following cheapest return flights from Boston (BOS) to Seoul (ICN) in September 2025 (see full year).

Return flights

13 Sep - 21 Sep	WestJet
17 Sep - 24 Sep	Cathay Pacific
29 Sep - 28 Oct	Cathay Pacific
09 Sep - 21 Sep	Cathay Pacific
11 Sep - 23 Sep	Cathay Pacific
13 Sep - 22 Sep	Cathay Pacific
14 Sep - 22 Sep	Cathay Pacific
14 Sep - 23 Sep	Cathay Pacific
05 Sep - 19 Sep	WestJet
24 Sep - 29 Sep	jetBlue
23 Sep - 28 Sep	Spirit Airlines
22 Sep - 01 Oct	jetBlue
29 Sep - 28 Oct	Delta	direct
22 Sep - 01 Oct	Delta	direct
24 Sep - 01 Oct	Air Canada
28 Sep - 05 Oct	Air Canada
27 Sep - 04 Oct	Air Canada

Also check the deals for one-way flights from Boston to Seoul 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.

Book a cheap hotel in Seoul

Cheap car rent in Seoul

Cheapest return flights from Boston to Seoul in September from $808

Return flights