Cheap flights from Seattle to Great Diamond Island

View AU$241 flight on Mon, 29 Sep. 2025Opens in a new window

Popular airlines from Seattle to Great Diamond Island

  • Plan, book, fly with confidence

  • trending down icon

    Be in the know

    Get alerts if flight prices drop or rise*
  • bex rewards loyalty icon

    Book smarter

    Save up to 35% on select hotels after you book a flight*
  • payments icon

    Earn twice

    Earn your airline miles on top of our rewards
    Sign in

Cheap Flights from Seattle (SEA) to Great Diamond Island (PWM)

Prices were available within the past 7 days for one-way flights and round trip tickets for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Mon, 29 Sep. - Mon, 20 Oct.
SEA
Seattle
PWM
Portland
AU$499 Return, found 1 day ago
AU$499
Return
found 1 day ago
Select American Airlines flight, departing Mon, 29 Sep. from Seattle to Portland, returning Mon, 20 Oct., priced at AU$499 found 1 day ago
American Airlines
Mon, 29 Sep. - Mon, 20 Oct.
SEA
Seattle
PWM
Portland
AU$549 Return, found 1 day ago
AU$549
Return
found 1 day ago
Select American Airlines flight, departing Mon, 29 Sep. from Seattle to Portland, returning Mon, 20 Oct., priced at AU$549 found 1 day ago
American Airlines
Mon, 29 Sep. - Mon, 20 Oct.
SEA
Seattle
PWM
Portland
AU$557 Return, found 1 day ago
AU$557
Return
found 1 day ago
Select American Airlines flight, departing Mon, 29 Sep. from Seattle to Portland, returning Mon, 20 Oct., priced at AU$557 found 1 day ago
Delta
Mon, 29 Sep. - Mon, 20 Oct.
SEA
Seattle
PWM
Portland
AU$645 Return, found 1 day ago
AU$645
Return
found 1 day ago
Select Delta flight, departing Mon, 29 Sep. from Seattle to Portland, returning Mon, 20 Oct., priced at AU$645 found 1 day ago
United
Mon, 29 Sep. - Mon, 20 Oct.
SEA
Seattle
PWM
Portland
AU$721 Return, found 1 day ago
AU$721
Return
found 1 day ago
Select United flight, departing Mon, 29 Sep. from Seattle to Portland, returning Mon, 20 Oct., priced at AU$721 found 1 day ago
Alaska Airlines
Mon, 29 Sep. - Mon, 20 Oct.
SEA
Seattle
PWM
Portland
AU$894 Return, found 1 day ago
AU$894
Return
found 1 day ago
Select Alaska Airlines flight, departing Mon, 29 Sep. from Seattle to Portland, returning Mon, 20 Oct., priced at AU$894 found 1 day ago

Find the cheapest month to fly from Seattle (SEA) to Portland (PWM)

September is typically the cheapest month to fly

From AU$348 - AU$729 per traveller.

Graph displaying average flight prices per month

*Available to Expedia members.