prices we've seen · United States fares · USD
The cheapest one-way fare from Ontario to San Francisco we have seen is $18 USD, departing Nov 21 (seen Oct 25): Frontier F9 1159, nonstop, 1h 33m.
Cheapest · One wayseen Oct 25
$18 USD
Frontier F9 1159 · Nov 21 · Nonstop · 1h 33m
Continue on the seller's site — $18Cheapest round tripseen Oct 20
$32 USD
Frontier F9 1159 · Dec 5 → Dec 9 · Nonstop · 3h 2m in all, both ways
Continue on the seller's site — $32a2bflight may earn a commission from the seller if you book after this click; the price you see is the seller's and does not change. How we rank, what we keep.
Checked Oct 26
Pick a month to search the day its cheapest fare leaves.
Each day's cheapest fare we've seen, nonstop and with stops. Cheapest first.
We may earn a commission from the seller · How we rank
The cheapest round trips we've seen on this route, on any dates, cheapest first.
We may earn a commission from the seller · How we rank
Compared with Ontario → San Francisco: $18 one way (Nov 21).
Marketing carriers; the operating airline is shown by the seller.
The cheapest one-way fare from Ontario to San Francisco we have seen is $18 USD, departing Nov 21 (seen Oct 25): Frontier F9 1159, nonstop, 1h 33m.
Nonstop fares were seen on 3 of the 3 departure dates; carriers seen: Frontier, United.
By month, Nov 2026 is the cheapest we've seen at $18 USD and Sep 2027 the most expensive at $243 USD — a spread of 1250%.
It is the cheapest fare we've seen for that date; the date beside it is the day it was seen, or our last check. We look again at least once a day for the routes people search, and stop showing a route's prices two days after our last look. The seller's page shows the price right now.
By price and duration only; commission never enters the order. Cheapest means cheapest among the fares we've seen for this route. A click that books may earn a2bflight a commission from the seller; the price you see is the seller's own. See how we rank and what we keep.