AirHint found the following cheapest return flights from Shannon (SNN) to Boston (BOS) in September 2025 (see full year).
25 Sep - 05 Oct | Ryanair | ||
05 Sep - 19 Sep | Aer Lingus | direct | |
25 Sep - 04 Oct | Aer Lingus | direct | |
25 Sep - 05 Oct | Aer Lingus | direct | |
01 Sep - 04 Sep | Ryanair | ||
01 Sep - 04 Sep | Aer Lingus | direct |
Also check the deals for one-way flights from Shannon to Boston 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.