A millstone is a stone used in gristmills, for grinding wheat or other grains.
Millstone may also refer to:
Media
"Millstone", a song on Brand New's 2006 album The Devil and God Are Raging Inside Me
"Millstone", a song on Eisley's 2013 album Currents
The Millstone (novel), a novel by Margaret Drabble
Places
Millstone Nuclear Power Plant, the only nuclear power generation site in Connecticut
Millstone River, a 38.6-mile-long (62.1-kilometer) tributary of the Raritan River in central New Jersey
Millstone Township, New Jersey, a township in Monmouth County, New Jersey, United States
Millstone, Mercer County, New Jersey, an unincorporated community located within East Windsor Township in Mercer County, New Jersey, United States
Millstone, New Jersey, a borough in Somerset County, New Jersey, United States
Millstone Township, Pennsylvania, a township in Elk County, Pennsylvania, United States
Other
Battle of Millstone, battle during the American Revolution
James Millstone (1930–1992), American journalist and editor
Millstone Coffee, a brand of coffee sold in the US
Millstone Grit, any of a number of coarse-grained sandstones of Carboniferous age which occur in the British Isles
Millstone Hill, a fully steerable dish antenna