AirHint found the following cheapest return flights from Ontario (ONT) to Frankfurt (FRA) in September 2025 (see full year).

Return flights

01 Sep - 15 Sep	British Airways
08 Sep - 22 Sep	British Airways
02 Sep - 09 Sep	United
04 Sep - 11 Sep	United
06 Sep - 13 Sep	United
10 Sep - 17 Sep	United
04 Sep - 18 Sep	British Airways
14 Sep - 21 Sep	United
16 Sep - 23 Sep	United
18 Sep - 25 Sep	United
24 Sep - 01 Oct	United
26 Sep - 03 Oct	United
29 Sep - 06 Oct	United
22 Sep - 06 Oct	British Airways
21 Sep - 01 Oct	British Airways
24 Sep - 02 Oct	British Airways
27 Sep - 10 Oct	Iberia
21 Sep - 05 Oct	British Airways
19 Sep - 03 Oct	Condor
20 Sep - 05 Oct	British Airways

Also check the deals for one-way flights from Ontario to Frankfurt in September.

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

Book a cheap hotel in Frankfurt

Cheap car rent in Frankfurt

Cheapest return flights from Ontario to Frankfurt in September from $734

Return flights