Flights London → San Francisco — September 20, 2026

One way · Economy · 1 adult · price per person

The cheapest itinerary observed for Sunday, September 20, 2026 on the London–San Francisco route: 1 stop itinerary (2 flights) via Montreal (YUL), from London Heathrow (LHR) to San Francisco International (SFO), first flight Air Canada AC8297, departs 2:05 PM, arrives 11:17 AM the next day, total travel time 29h 12m including layovers, flight time 13h 42m (layovers excluded), $623 per person. Fare as listed by Aviasales: carry-on bag not included (personal item only), checked bag not included, changes not allowed, non-refundable. Price found in an Aviasales search on September 7, 2026 and read by AirSource on September 10, 2026, 19:03 UTC: it is not guaranteed and is confirmed on Aviasales at booking time. The cheapest direct flight observed: United Airlines UA9106, from London Heathrow (LHR) to San Francisco International (SFO), departs 4:15 PM, arrives 7:15 PM, direct, 11h, $1,510 per person. Fare as listed by Aviasales: carry-on bag not included (personal item only), checked bag not included, changes allowed for a fee, non-refundable.