The Ambergate, Nottingham and Boston and Eastern Junction Railway was a British railway company, which hoped to connect Lancashire with the port of Boston, in Lincolnshire, England. It was authorised in 1846 but was unable to raise much money. It opened a standard gauge line from a junction near Nottingham to Grantham in 1853. At Nottingham it was to rely on the Midland Railway, but that company was hostile and obstructive.
The Ambergate company was leased to the Great Northern Railway in 1855, and they built their own Nottingham station, opened in 1857. In 1860 the company changed its name to the Nottingham and Grantham Railway and Canal Company. In 1875 the Great Northern Railway opened a line into Derbyshire and the former Nottingham to Grantham line became an important trunk route, particularly for goods and mineral traffic.
The original line from Colwick to Grantham is still in use as the Nottingham–Grantham line. The freight traffic has greatly diminished, but the line is used for long distance passenger trains between Liverpool and Norwich, as well as from Nottingham to Skegness.