Direct flights from Ontario to Seattle ONT → SEA
Alaska Airlines, Delta Air Lines and Frontier Airlines operate nonstop flights from Ontario (ONT) to Seattle (SEA). The nonstop flight takes around ~1h 56m, covering 957 miles (1,540 km). Updated 28 June 2026.
ONT
→
SEA
Round trip
1 adult
Economy
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Alaska Airlines
AS
Delta Air Lines
DL
Frontier Airlines
F9
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Frequently asked questions
Is there a direct flight from Ontario to Seattle?
Yes, Alaska Airlines, Delta Air Lines and 1 more airline operate nonstop flights from Ontario (ONT) to Seattle (SEA).
Which airlines fly direct from Ontario to Seattle?
Alaska Airlines, Delta Air Lines, Frontier Airlines operate nonstop flights from Ontario to Seattle.
How long is the flight from Ontario to Seattle?
The nonstop flight from Ontario to Seattle takes ~1h 56m (approximately 1540 km).