Your next trip, last seen at €101
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
- €101, departing 13 Dec 2026 (Last checked: 21 Oct 2026)One-way fareCheck live prices for this route
- Airlines seen
- Allegiant Air, Breeze Airways, Frontier Airlines, JetBlue, United Airlines
- Typical journey time
- 21h 14m
About this route
Explore the fares we observed from Boston to Key West. Prices move often, so pick your dates to see the latest options.
- Route distance
- 2,211 km
- Typical journey time
- 21h 14m
- Seen on fares with a connection
- JetBlue, Frontier Airlines, Allegiant Air, Breeze Airways, United Airlines
- Alternative airports
- PSM
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
Non-stop airlines seen on this route
| Airline | Non-stop days / priced days | Fastest non-stop |
|---|---|---|
| JetBlue | 22 / 85 |
Departure days with a non-stop fare checked in the last 14 days. A carrier listed here had a non-stop fare on at least 3 days; schedules may differ.
Airport to city: straight-line distance
- Portsmouth International Airport at Pease (PSM) → Boston, city gazetteer reference point (42.3584, -71.0598): ≈ 82 km.
- Key West International Airport (EYW) → Key West, city gazetteer reference point (24.5557, -81.7826): ≈ 2 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 Boston to Key West: Allegiant Air, from €101 (checked 21 Oct 2026).
| Airline | Lowest fare | Priced days |
|---|---|---|
| Allegiant Air | €101Dec 13, 2026 | 13 |
| Frontier Airlines | €120Dec 14, 2026 | 28 |
| Breeze Airways | €121Jan 11, 2027 | 4 |
| JetBlue | €157Dec 7, 2026 | 38 |
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 Boston to Key West?
The lowest fare Routavio has observed is €101, found on 21 Oct 2026. Prices move, so read it as a floor rather than a quote.
When is the cheapest month to fly from Boston to Key West?
In our observations December 2026 is the cheapest month so far, at €101.
Are there direct flights from Boston to Key West?
Our data holds no non-stop flight from Boston to Key West. The fares on this page include at least one stop.
Which airlines fly from Boston to Key West?
Routavio has seen these carriers on the route: Allegiant Air, Breeze Airways, Frontier Airlines, JetBlue, United Airlines.
How long does the flight from Boston to Key West take?
Across the 90 fares Routavio observed, the average journey time is 18h 33m, including any stops. Individual departures vary; the fastest observed flight is listed in the route facts above.
Which airlines had non-stop offers on at least 3 departure dates from Boston to Key West?
For Boston to Key West, examples of observed one-way non-stop offers checked within the last 14 days: JetBlue (22). Each number counts distinct departure dates, not weekly flights; check current availability in search.
Which airline has the lowest fare from Boston to Key West?
Cheapest airline from Boston to Key West: Allegiant Air, from €101 (checked 21 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: 29 Oct 2026