Dallas (DFW) to Seattle (SEA): 1,658 miles (2,668 km) great-circle, about 3h 50m nonstop by our estimate. Cheapest fare observed: $276 round-trip on Frontier, with 1 stop, departing July 4, 2026.
$276 round-trip, Frontier F93885, departing 2026-07-04 at 22:49, returning 2026-07-11. The recorded itinerary left on a Saturday, returning on a Saturday 7 nights later; the fare was observed 70 days before departure. "Book this flight" opens Kiwi.com with the same airline and dates.
At $276, it ranked 20th of the 30 round-trip fares we recorded from DFW (median $198). That is 16.6 cents per great-circle mile (round-trip price over one-way distance), close to the DFW median of 15.9 cents across 30 round-trip routes.
Routes from DFW of similar length: Boston (1,559 mi) at $128 and San Salvador (1,435 mi) at $490.
Frontier had the cheapest fare on 18 of 30 DFW routes. It is the 9th longest of the 30 routes we track from DFW.
Of 18 departure airports with a fare to Seattle, Dallas (DFW) ranked 13th at $276. 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 Dallas (DFW), was $200 round-trip on Alaska Airlines, nonstop, departing July 23, 2026. Seattle to Dallas flights.
Travelpayouts fares (cheapest per route, observed April 25, 2026); OurAirports coordinates and elevations; IANA zones America/Chicago, America/Los_Angeles; flight time is our estimate.