Your next trip, last seen at €149
Lowest observedAllegiant Air · 1 stop · One wayWhen to fly
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The lowest fare we observed for each month. Open a month to see its days, then pick your outbound and return. A day with no price is one we will search for you.
One-way fare
- Lowest observed
- €149, departing 4 Jan 2027 (Last checked: 17 Oct 2026)One-way fareCheck live prices for this route
- Airlines seen
- Air Canada, Alaska Airlines, Allegiant Air, Breeze Airways, Frontier Airlines, United Airlines, WestJet (7)
- Typical journey time
- 21h 43m
About this route
Explore the fares we observed from Sioux Falls to Seattle. Prices move often, so pick your dates to see the latest options.
- Route distance
- 2,033 km
- Typical journey time
- 21h 43m
- Seen on fares with a connection
- Allegiant Air, United Airlines, Alaska Airlines, Frontier Airlines, WestJet
- Alternative airports
- BFI
Route-level information; individual journeys vary.
We have not observed non-stop service on this route; the fares shown include at least one stop.
A clearer picture of your fare
Airport to city: straight-line distance
- Sioux Falls Regional Airport (FSD) → Sioux Falls, city gazetteer reference point (43.5473, -96.7283): ≈ 4 km.
- King County International Airport - Boeing Field (BFI) → Seattle, city gazetteer reference point (47.6062, -122.3321): ≈ 9 km.
- Seattle–Tacoma International Airport (SEA) → Seattle, city gazetteer reference point (47.6062, -122.3321): ≈ 18 km.
Approximate distances calculated from coordinates, not road distances or travel times. These airports serve the city; they are not confirmed endpoints of an offer.
Lowest one-way fare we saw per airline
Cheapest airline from Sioux Falls to Seattle: Allegiant Air, from €149 (checked 17 Oct 2026).
| Airline | Lowest fare | Priced days |
|---|---|---|
| Allegiant Air | €149Jan 4, 2027 | 39 |
| Frontier Airlines | €190Dec 7, 2026 | 9 |
| United Airlines | €309Nov 17, 2026 | 19 |
| Alaska Airlines | €390Dec 24, 2026 | 8 |
One-way fares checked in the last 14 days. An airline listed here had a fare on at least 3 departure days. Each figure is the lowest we saw, not a guaranteed fare. Connecting itineraries are included; the date is the departure day of that fare.
Frequently asked
How much is a flight from Sioux Falls to Seattle?
The lowest fare Routavio has observed is €149, found on 17 Oct 2026. Prices move, so read it as a floor rather than a quote.
When is the cheapest month to fly from Sioux Falls to Seattle?
In our observations January 2027 is the cheapest month so far, at €149.
Are there direct flights from Sioux Falls to Seattle?
Our data holds no non-stop flight from Sioux Falls to Seattle. The fares on this page include at least one stop.
Which airlines fly from Sioux Falls to Seattle?
Routavio has seen these carriers on the route: Air Canada, Alaska Airlines, Allegiant Air, Breeze Airways, Frontier Airlines, United Airlines, WestJet (7).
How long does the flight from Sioux Falls to Seattle take?
Across the 84 fares Routavio observed, the average journey time is 21h 52m, including any stops. Individual departures vary; the fastest observed flight is listed in the route facts above.
How many of the observed Sioux Falls to Seattle fares were non-stop?
None of the 84 fares we observed was non-stop; every one included at least one stop. That describes our observations, not every flight that operates.
Which airline has the lowest fare from Sioux Falls to Seattle?
Cheapest airline from Sioux Falls to Seattle: Allegiant Air, from €149 (checked 17 Oct 2026).
How observed prices work, what "No data" means and what a fare includes: Read the flight price guide
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Recently observed fares. Prices may change.
Last checked: 24 Oct 2026