Direct (nonstop) flights from Seattle to Ontario
3 airlines fly nonstop from Seattle Tacoma International (SEA) to Ontario International Airport (ONT). It's 956 miles (1,538 km), about 2h 42m in the air. Operated by Alaska Airlines, Delta Air Lines, Frontier Airlines.
Alaska Airlines
Delta Air Lines
Frontier Airlines
Route data last updated: May 31, 2026
Airlines with non-stop flights
AS
Alaska Airlines
DL
Delta Air Lines
F9
Frontier Airlines
Alternative Routes
Other ways to fly from Seattle to Ontario with one stop · direct emits 161 kg CO₂ per passenger
Looking for the return flight?
ONT → SEA: Flights from Ontario to SeattleOther direct flights from Seattle
Direct flights from Ontario (ONT)
Frequently Asked Questions
How long is the direct flight from Seattle to Ontario?
A nonstop flight from Seattle (SEA) to Ontario (ONT) takes approximately 2 hours and 42 minutes. The distance is 956 miles (1,538 km).
Which airlines fly nonstop from Seattle to Ontario?
3 airlines: Alaska Airlines, Delta Air Lines, Frontier Airlines.
Is there a nonstop flight from Seattle to Ontario?
Yes. 3 airlines: Alaska Airlines, Delta Air Lines, Frontier Airlines.
How far is Seattle from Ontario?
The flight distance from Seattle to Ontario is 956 miles (1,538 km), measured as the great-circle (shortest air) distance. That's roughly the same distance as New York to Miami.
What type of aircraft flies from Seattle to Ontario?
At 2h 42m, this route typically uses narrow-body or mid-range jets — Boeing 737 MAX or Airbus A320neo. Varies by airline.
What is the carbon footprint of a flight from Seattle to Ontario?
Roughly 161 kg CO2 per passenger one-way. That's about the same as driving 805 km.
Is the return flight from Ontario to Seattle also nonstop?
Yes — nonstop flights run both ways. Flight time may differ slightly due to wind patterns.
When is the cheapest time to fly from Seattle to Ontario?
Midweek flights (Tue/Wed) outside holiday peaks are usually cheapest. 3-6 weeks ahead is a good window for this route. Use "Check Prices" above to compare.
How early should I arrive at Seattle Tacoma International for this flight?
1.5-2 hours for domestic. Add more time during holidays or busy travel weekends.