Montreal (YUL) to San Francisco (SFO): 2,533 miles (4,076 km) great-circle, about 5h 35m nonstop by our estimate. Cheapest fare observed: $320 round-trip on WestJet, with 2 stops, departing July 17, 2026.
$320 round-trip, WestJet WS859, departing 2026-07-17 at 06:45, returning 2026-07-20. The recorded itinerary left on a Friday, returning on a Monday 3 nights later; the fare was observed 83 days before departure. "Book this flight" opens Kiwi.com with the same airline and dates.
At $320, it ranked 4th of the 30 round-trip fares we recorded from YUL (median $752). That is 12.6 cents per great-circle mile (round-trip price over one-way distance), below the YUL median of 21.8 cents across 30 round-trip routes.
Routes from YUL of similar length: Guatemala City (2,347 mi) at $486 and Mexico City (2,307 mi) at $355.
WestJet had the cheapest fare on 7 of 30 YUL routes. It is the 20th longest of the 30 routes we track from YUL.
Of 19 departure airports with a fare to San Francisco, Montreal (YUL) ranked 16th at $320. Lowest: $126 from Los Angeles (LAX); highest: $483 from New York (JFK); 6 nonstop. Cheapest-fare airlines (routes): Frontier (13), Southwest (3), American Airlines (1), United Airlines (1) and WestJet (1).
That depends on your passport and trip, so check the official source for United States: U.S. Customs and Border Protection: international visitors. Connecting elsewhere? Check that country's transit rules too.
Travelpayouts fares (cheapest per route, observed April 25, 2026); OurAirports coordinates and elevations; IANA zones America/Toronto, America/Los_Angeles; flight time is our estimate.