United Airlines Flights from Seattle to Billings

United Airlines on this route

United Airlines serves SEA–BIL through its hub network, usually with one connection. The nonstop flight time is about 1h 58m.

Fare classes available: Basic Economy, Economy, Economy Plus, Premium Plus / First / Polaris. United has no change fees on Economy and above for travel within the US or between the US and Mexico, the Caribbean, or international destinations originating in the US. Fare difference applies.

Recorded lows on SEA–BIL start at $364 one-way. That figure comes from cached search data and moves with demand, so treat it as a benchmark for what a good price looks like rather than a guaranteed fare.

Delta Air Lines and United Airlines both operate hubs at one end of this route, so nonstop or single-connection service is usually available, along with American Airlines and Southwest Airlines. Our agents can book any of them and compare fare classes side by side.

Expect roughly 1h 58m nonstop for the 662 miles. On routes this length, basic economy and standard economy often differ by less than a checked-bag fee, so it pays to price the higher fare with the bag included.

When to fly

West Coast and Mountain departures spike over summer holidays and the December break; January (after New Year), late April, May, and September are usually the cheapest windows.

Midweek travel almost always beats weekends on price here. If your dates are flexible by a day or two, tell the agent; shifting a Friday departure to Thursday or a Sunday return to Monday is the single most reliable way to cut the fare.

For domestic travel, booking three to eight weeks ahead usually captures the best price. Inside two weeks, fares climb; more than four months out, airlines have not yet released their cheapest inventory.