AirHint found the following cheapest one-way flights from Philadelphia (PHL) to Boston (BOS) in August 2025 (see full year).

One-Way flights

07 Aug	Frontier Airlines	direct
05 Aug	Frontier Airlines	direct
03 Aug	Frontier Airlines	direct
14 Aug	Frontier Airlines	direct
24 Aug	Frontier Airlines	direct
31 Aug	Frontier Airlines	direct
12 Aug	Frontier Airlines	direct
21 Aug	Frontier Airlines	direct
17 Aug	Frontier Airlines	direct
28 Aug	Frontier Airlines	direct

Also check the deals for return flights from Philadelphia to Boston in August.

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 Philadelphia to Boston in August from $39

One-Way flights