C$ 174 Find Cheap Flights from Seattle to Ontario – Compare and Save

These are the earliest and latest flight times available from Seattle to Ontario:

• Earliest: departs at 7:30 am and lands at 10:15 am
• Latest: departs at 9:20 pm and lands at 12:05 am.

The flight takes about 2h 45m.

Only Economy Class is available on flights from Seattle to Ontario.

A direct flight from Seattle to Ontario takes 2h 45m, covering 2,477 km.

No, a passport is not required for this domestic route, but you will need a real ID-compliant driver's license, a state ID, or another TSA-accepted form of identification.

Round-trip flights from Seattle to Ontario range from C$ 282 to C$ 533, with an average of C$ 401 over the past 12 months. Anything below C$ 282 counts as a good deal.

Last-minute fares on this route – booked within 2 weeks of departure – run 36% above the route average of C$ 401. Book 11 weeks before departure for the lowest fares.

On this route, layover flights are cheaper than direct options on average. Layover fares average C$ 362 round-trip via Sacramento Intl (SMF), compared to C$ 403 for direct.

There is no standard. Checked bag policies vary by airline on this route. Most carriers charge C$ 49–C$ 140 for the first checked bag in economy. Premium fares and elite status bookings typically include a free checked bag.

The Boeing 737-800 Passenger/BBJ2 (winglets) family is used most often on this route, operated mainly by Alaska Airlines. Other aircraft seen on the route include Airbus A321neo variants.

Morning is the busiest departure period on Seattle to Ontario flights, with 43% leaving in that window. Afternoon departures account for 29%, Evening flights for 28%, and Night flights for 0%.

Yes. Based on fares seen in the past 5 days, round-trip prices on this route showed a wide range, from about C$ 347 to C$ 1,781. That means the highest observed fare was about 5x higher than the lowest one.

Two airlines offer in-flight Wi-Fi on Seattle to Ontario flights:

• Alaska Airlines
• Delta

Pricing varies by airline and fare class. Some plans are included with the ticket or loyalty program; others are paid add-ons priced by flight length.

One-way fares from Seattle to Ontario are currently lower than usual. Average one-way flight prices are about C$ 191, which is 28% below the typical average for this route.

Ontario Airport (ONT) hosts 5 major car rental companies, with daily rates starting from around C$ 25 for economy cars. Top options include:
• Fox
• Thrifty
• Europcar
• Dollar
• Alamo

Flights from Seattle to Ontario usually depart from Seattle/Tacoma Intl (SEA) and arrive at Ontario (ONT).

One-stop flights from Seattle to Ontario most commonly connect through:

• Denver Intl (DEN) – 41% of one-stop connections
• Sacramento Intl (SMF) – 38% of one-stop connections
• San Francisco (SFO) – 9% of one-stop connections
• Las Vegas Harry Reid Intl (LAS) – 6% of one-stop connections

Denver Intl (DEN) handles the largest share of one-stop connections on this route.

Yes. Being flexible with your travel dates can save you up to 26% on the Seattle to Ontario route. Thursday is the cheapest departure day at C$ 362 round-trip on average, while Sunday is the most expensive at C$ 485, a difference of C$ 122. KAYAK's flexible dates feature shows options up to 3 days before and after your selected dates, making it easier to compare nearby fares.

3 airlines operate flights between Seattle and Ontario. The airlines offering direct flights on this route include:

• Alaska Airlines
• Delta
• Frontier

Flying via Sacramento Intl (SMF) gives the shortest average 1-stop total travel time at 4h 29m, compared with 4h 36m via Portland (PDX) and 4h 56m via San Francisco (SFO).

Ontario Convention Center is one of the most viewed places in Ontario on KAYAK.

Among airlines operating Seattle to Ontario flights:

• Frontier: offers free seat selection
• Alaska Airlines: offers extra legroom; offers free seat selection
• Delta: offers extra legroom; offers free seat selection

Extra legroom and free seat selection availability depends on fare class and route.

Here are some options for this route, based on selected ticket types and cabin classes:

• Frontier: a carry-on bag and a checked bag in Economy Class
• Alaska Airlines: a carry-on bag and a checked bag in Economy Class
• Delta: a carry-on bag and a checked bag in First Class

Bag allowance can vary by ticket type, cabin class, route, and airline, so travellers should check the fare details before booking.