South Acton is a passenger rail station on the MBTA Commuter Rail Fitchburg Line, in Acton, Massachusetts off Route 27 near Route 2. It is the busiest station on the Fitchburg line, averaging 902 weekday passenger boardings and thus generating 15% of the line's traffic. It serves as a park and ride station for Acton and other suburbs of Boston, with a 287-space parking lot owned by the town.