East Granby is a town in the Capitol Planning Region, Connecticut, United States. The population was 5,214 at the 2020 census.

Old New-Gate Prison is a former prison and mine site on New-Gate Road in East Granby, Connecticut. It is now operated by the state of Connecticut as the Old New-Gate Prison & Copper Mine Archaeological Preserve. Previously closed for restoration since 2009, it was re-opened on July 14, 2018. The site includes a colonial-era copper mine, which visitors are able to explore through a guided tour, and the remains of the state's first official prison, which was used between 1776 and 1782 to house prisoners of war from the American Revolutionary War. The site was designated a National Historic Landmark in 1972.