AirHint found the following cheapest one-way flights from Seattle (SEA) to Singapore (SIN) in August 2025 (see full year).

One-Way flights

19 Aug	Delta
12 Aug	Delta
17 Aug	United
23 Aug	Alaska Airlines
16 Aug	Hawaiian Airlines
01 Aug	Korean Air
23 Aug	Singapore Airlines	direct
17 Aug	Singapore Airlines	direct
01 Aug	Singapore Airlines	direct

Also check the deals for return flights from Seattle to Singapore in August.

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 one-way flights from Seattle to Singapore in August from 336€

One-Way flights