Cheap flights from Seattle to Boston from $121

The cheapest month to fly to Portland, Maine from Seattle is in January. Flight prices, which tend to average around $308, are often lower during this time because this is during the off-season. If you aren’t able to travel to Portland, Maine during the month of January, then flying in October is also cheap. Prices for this month can be found on momondo for an average of $426.

You are more likely to see cheaper flights to Portland, Maine from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to Portland, Maine for around $510 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Portland, Maine from Seattle for as low as $382 on momondo.

You could potentially save up to 30% on your flight if you consider stops on a Seattle to Portland, Maine flight.

As of February 2026, prices for Seattle to Portland, Maine flights are approximately 16% more expensive when compared to flights at the same time last year.

Delta, United Airlines, and Southwest are the most popular carriers operating from Seattle/Tacoma Intl to Portland

Delta, Alaska Airlines and JetBlue are the top three most popular airlines that fly to Portland, Maine from Seattle according to our data. Delta is the first choice among our users, with 39% of people opting to fly with this airline when traveling to Portland, Maine. Keep in mind that there are 8 different airlines that fly to Portland, Maine on a routine basis, so you have a few additional options to choose from.

Philadelphia (PHL) was the most common stop: 33% of momondo users choosing 1-stop flights on this route connected there.

Flights via Washington, D.C. (IAD) offer the lowest average round-trip price of $265.

Flights connecting via Washington, D.C. (IAD) have the shortest average one-way travel time: 7h 59m.

Washington, D.C. (IAD) has the shortest average layover time for this route: 1h 07m.