The Berkshire Subdivision is a railroad line owned by CSX Transportation in the U.S. states of Massachusetts and New York. The line runs from near Springfield, Massachusetts west to Schodack, New York (near Albany) along a former New York Central Railroad line. Its east end is in Wilbraham, east of Springfield, at the west end of the Boston Subdivision. Its west end is at the east end of the Alfred H. Smith Memorial Bridge, at a junction with the Castleton Subdivision and Schodack Subdivision. Along the way, the line junctions Amtrak's Post Road Branch (over which CSX has trackage rights) in Schodack.
The Western Railroad opened east of Springfield in 1839, and from Springfield west to the New York state line in 1841. In 1842, the portion of the Boston-Albany line in New York was completed by the Albany and West Stockbridge Railroad. The Hudson River Connecting Railroad opened the piece of the current Berkshire Subdivision west of the Post Road Branch junction in 1924. The line became part of the Boston and Albany Railroad, New York Central, and Conrail through leases, mergers, and takeovers, and was assigned to CSX in the 1999 breakup of Conrail.