The Fitchburg and Worcester Railroad was a railroad in Massachusetts. It was incorporated in 1840 to provide a rail connection between Fitchburg and Worcester. Service began on February 11, 1850, running 18 miles from Fitchburg through Leominster and Sterling to Sterling Junction, where it connected with the Worcester and Nashua Railroad.
In July 1866, the nearby Boston, Clinton and Fitchburg Railroad opened a 14-mile extension of its line from Northborough and joined with the Fitchburg and Worcester Railroad at Pratts Junction in Sterling via the towns of Berlin and Clinton. The two railroads merged in 1869. On June 1, 1876, The Boston, Clinton, and Fitchburg Railroad merged with the New Bedford Railroad to form the Boston, Clinton, Fitchburg and New Bedford Railroad, which was leased to the Old Colony Railroad in 1879 and then consolidated into the Old Colony network on March 5, 1883. In 1893, the Old Colony Railroad was leased to the New York, New Haven and Hartford Railroad.