Cheapest return flights from Seattle to Singapore in September from $668

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

Return flights

16 Sep - 28 Sep Singapore Airlines direct
01 Sep - 18 Sep Korean Air
14 Sep - 21 Sep Air Canada
23 Sep - 27 Sep Air Canada
05 Sep - 22 Sep Air Canada
06 Sep - 23 Sep Air Canada
13 Sep - 28 Sep Korean Air
14 Sep - 16 Sep Korean Air
23 Sep - 27 Sep Singapore Airlines direct

Also check the deals for one-way flights from Seattle to Singapore in September.

Skyscanner

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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