Chicago (ORD) to Seattle (SEA): 1,716 miles (2,762 km) great-circle, about 3h 55m nonstop by our estimate. Cheapest fare observed: $241 round-trip on Alaska Airlines, nonstop, departing June 6, 2026.
$241 round-trip, Alaska Airlines AS329, departing 2026-06-06 at 10:00, returning 2026-06-21. The recorded itinerary left on a Saturday, returning on a Sunday 15 nights later; the fare was observed 42 days before departure. "Book this flight" opens Kiwi.com with the same airline and dates.
At $241, it ranked 17th of the 30 round-trip fares we recorded from ORD (median $221). That is 14.0 cents per great-circle mile (round-trip price over one-way distance), below the ORD median of 16.6 cents across 30 round-trip routes.
Routes from ORD of similar length: Guadalajara (1,733 mi) at $199 and Los Angeles (1,741 mi) at $167.
ORD to SEA is the only one of 30 ORD routes where Alaska Airlines priced cheapest. It is the 17th longest of the 30 routes we track from ORD.
Of 18 departure airports with a fare to Seattle, Chicago (ORD) ranked 10th at $241. 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 Chicago (CHI), was $735 round-trip on American Airlines, nonstop, departing April 26, 2026. Seattle to Chicago 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.