Phoenix (PHX) to Seattle (SEA): 1,107 miles (1,782 km) great-circle, about 2h 45m nonstop by our estimate. Cheapest fare observed: $279 round-trip on Frontier, with 1 stop, departing April 25, 2026.
$279 round-trip, Frontier F91820, departing 2026-04-25 at 21:24, returning 2026-04-29. The recorded itinerary left on a Saturday, returning on a Wednesday 4 nights later; the fare was observed 0 days before departure. "Book this flight" opens Kiwi.com with the same airline and dates.
At $279, it ranked 21st of the 30 round-trip fares we recorded from PHX (median $231). That is 25.2 cents per great-circle mile (round-trip price over one-way distance), above the PHX median of 17.4 cents across 30 round-trip routes.
Routes from PHX of similar length: Guadalajara (1,039 mi) at $207 and Portland (1,010 mi) at $176.
Frontier had the cheapest fare on 19 of 30 PHX routes. It is the 20th longest of the 30 routes we track from PHX.
Of 18 departure airports with a fare to Seattle, Phoenix (PHX) ranked 14th at $279. Lowest: $122 from Houston (IAH); highest: $690 from Punta Cana (PUJ); 5 nonstop. Cheapest-fare airlines (routes): Frontier (13), Alaska Airlines (2), Air Canada (1), Southwest (1) and United Airlines (1).
The reverse, Seattle (SEA) to Phoenix (PHX), was $279 round-trip on Alaska Airlines, nonstop, departing May 22, 2026. Seattle to Phoenix flights.
Travelpayouts fares (cheapest per route, observed April 25, 2026); OurAirports coordinates and elevations; IANA zones America/Phoenix, America/Los_Angeles; flight time is our estimate.