AirHint found the following cheapest one-way flights from Jacksonville (JAX) to Philadelphia (PHL) in September 2025 (see full year).

One-Way flights

03 Sep	Southwest Airlines
04 Sep	Frontier Airlines	direct
26 Sep	Frontier Airlines	direct
28 Sep	Frontier Airlines	direct
29 Sep	Frontier Airlines	direct
05 Sep	Frontier Airlines	direct
07 Sep	Frontier Airlines	direct
08 Sep	Frontier Airlines	direct
11 Sep	Frontier Airlines	direct
12 Sep	Frontier Airlines	direct

Also check the deals for return flights from Jacksonville to Philadelphia 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.

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Cheapest one-way flights from Jacksonville to Philadelphia in September from $89

One-Way flights