Green Hill is a small unincorporated community in Medina Township, Warren County, in the U.S. state of Indiana.

A post office was established on December 2, 1837 as Poolesville, in honor of the town's first resident physician, Dr. Poole — it retained the name until August 13, 1904.

[4] In common with many other small Midwestern communities, Green Hill diminished during the 20th century as its rural population dwindled or moved to more urban areas.

One of Green Hill's most notable natives is NASA astronaut Donald E. Williams, who served as pilot on the Space Shuttle Discovery (STS-51-D) in 1985 and as commander of the Atlantis (STS-34) in 1989.

[3][6] Civil War general George Day Wagner was raised on a farm near Green Hill, and is buried in Armstrong Cemetery.