The Berkshire Subdivision is a railroad line owned by CSX Transportation in the U.S. states of Massachusetts and New York.

Along the way, the line junctions Amtrak's Post Road Branch (over which CSX has trackage rights) in Schodack.

[2][3] Amtrak operates trains over the Berkshire Subdivision east of the junction with the Post Road Branch.

The seasonal Berkshire Flyer runs as far as Pittsfield, while the Boston section of the long-distance Lake Shore Limited follows the line through to its eastern terminus.

[5] The Hudson River Connecting Railroad opened the piece of the current Berkshire Subdivision west of the Post Road Branch junction in 1924.