This is live pricing from Travelpayouts' aggregation of 40+ booking engines. The $231 fare is the cheapest current round-trip from Phoenix (PHX) to ONT on Frontier flight F91019, departing 2026-08-07 at 07:45 with return on 2026-08-09.

Clicking "Book this flight" opens Kiwi.com with this exact flight pre-filtered — same airline, same dates, same passenger count.