United States Β· 957 miles (1,540 km)

Ontario (ONT) to Seattle (SEA) flights

Alaska Atmos Rewards logo
7,500 milesCheapest economy award, one way, with Alaska Atmos Rewards

An economy award from Ontario (ONT) to Seattle (SEA) starts at 7,500 miles one way with Alaska Atmos Rewards on Alaska Airlines, plus taxes and fees from $5.60. 3 airlines fly nonstop from Ontario (ONT) to Seattle (SEA): Alaska Airlines, Delta Air Lines and Frontier Airlines. The two airports are 957 miles (1,540 km) apart. Alaska Airlines is in oneworld and Delta Air Lines is in SkyTeam. There are also 11 ways to fly it with one stop, through Portland, Sacramento and San Jose and more.

How many miles ONT to SEA costs

Economy, one way, on the nonstop flights, from the Award Flight Pricer's award charts. Ranges run off-peak to peak; "from" is the floor of a dynamic price.

ProgramEconomyTaxes and fees
Alaska Atmos RewardsOn Alaska Airlines7,500$5.60
Iberia ClubOn Alaska Airlines9,000$5.60
Starlux (COSMILE)On Alaska Airlines10,000$38.60
Virgin Atlantic Flying ClubOn Delta Air Lines11,000$5.60
JAL Mileage BankOn Alaska Airlines12,000$5.60
American AAdvantageOn Alaska Airlines12,500$5.60
Qatar Airways Privilege ClubOn Alaska Airlines13,000$5.60
Cathay Pacific Asia MilesOn Alaska Airlines15,000$5.60
SAS EuroBonusOn Delta Air Lines15,000$56–112
British Airways ClubOn Alaska Airlines16,000$5.60
Qantas Frequent FlyerOn Alaska Airlines16,100$5.60
Finnair PlusOn Alaska Airlines17,500$5.60

Business and first class prices are in the Award Flight Pricer. Chart prices need award space on your date, so search it before you transfer points.

Compare every program in the Award Flight Pricer

Airlines flying nonstop from ONT to SEA

Book ONT to SEA with points

Loyalty programs that can book at least one of the nonstop airlines, from the Award Booking Guide.

ONT to SEA with one stop

11 connections, most direct first. 2-stop routings and flight times are in Routes with Pro.

  • Via Portland (PDX)Alaska Airlines the whole way
    Alaska Airlines logo
    Frontier Airlines logo
    Alaska Airlines logo
    Delta Air Lines logo
  • Via Sacramento (SMF)Southwest Airlines the whole way
    Southwest Airlines logo
    Frontier Airlines logo
    Alaska Airlines logo
    Delta Air Lines logo
    Southwest Airlines logo
  • Via San Jose (SJC)Southwest Airlines the whole way
    Southwest Airlines logo
    Alaska Airlines logo
    Delta Air Lines logo
    Southwest Airlines logo
  • Via Oakland (OAK)Southwest Airlines the whole way
    Southwest Airlines logo
    Frontier Airlines logo
    Alaska Airlines logo
    Southwest Airlines logo
  • Via Santa Rosa (STS)Alaska Airlines the whole way
    Alaska Airlines logo
    Alaska Airlines logo
  • Via San Francisco (SFO)United Airlines the whole way
    United Airlines logo
    Frontier Airlines logo
    Alaska Airlines logo
    Delta Air Lines logo
    United Airlines logo
  • Via Boise (BOI)Alaska Airlines the whole way
    Alaska Airlines logo
    Alaska Airlines logo
    Delta Air Lines logo
  • Via Las Vegas (LAS)Southwest Airlines and Frontier Airlines the whole way
    Southwest Airlines logo
    Frontier Airlines logo
    Alaska Airlines logo
    Delta Air Lines logo
    Southwest Airlines logo
    +2
  • Via Salt Lake City (SLC)Delta Air Lines the whole way
    Delta Air Lines logo
    Alaska Airlines logo
    Delta Air Lines logo
  • Via Phoenix (PHX)American Airlines and Southwest Airlines the whole way
    American Airlines logo
    Southwest Airlines logo
    American Airlines logo
    Alaska Airlines logo
    Delta Air Lines logo
    +1
  • Via Denver (DEN)Frontier Airlines, United Airlines and 1 more the whole way
    Frontier Airlines logo
    United Airlines logo
    Southwest Airlines logo
    Alaska Airlines logo
    Delta Air Lines logo
    Frontier Airlines logo
    +3

ONT to SEA: common questions

How many miles does ONT to SEA cost?

In economy it starts at 7,500 miles one way with Alaska Atmos Rewards on Alaska Airlines, plus taxes and fees from $5.60. Next cheapest: Iberia Club (9,000), Starlux (COSMILE) (10,000) and Virgin Atlantic Flying Club (11,000). These are award chart prices from the Award Flight Pricer. Programs that price dynamically can cost more on busy dates, so check yours before you transfer points. Business and first class prices are in the pricer too.

Which airlines fly nonstop from ONT to SEA?

Alaska Airlines (oneworld), Delta Air Lines (SkyTeam) and Frontier Airlines fly nonstop from Ontario (ONT) to Seattle (SEA).

How far is Ontario from Seattle by plane?

Ontario (ONT) and Seattle (SEA) are 957 miles (1,540 km) apart along the great circle, the shortest path a flight can take. Connections add distance on top.

Which points programs can book ONT to SEA award flights?

17 programs can book at least one of the nonstop airlines: Aeromexico Rewards, Air France-KLM Flying Blue, Alaska Atmos Rewards, American AAdvantage, British Airways Club, Cathay Pacific Asia Miles, China Eastern Eastern Miles, Delta SkyMiles and 9 more. Which flights each can book depends on its partners, so check the airline before you transfer points.

Where can I connect between Ontario and Seattle?

The most direct connections are through Portland (PDX), Sacramento (SMF), San Jose (SJC), Oakland (OAK) and Santa Rosa (STS). On 11 of them the same airline flies both flights, for example Alaska Airlines through Portland.

More routes

Routes are scheduled nonstop flights. The route data is refreshed monthly; this list was last checked November 11, 2026. Seasonal routes and new launches can be missing or end early, so confirm with the airline before you book. Distances are great-circle, the shortest path between the two airports.