Old Union Church and Cemetery is a historic church and cemetery located in Reeve Township, Daviess County, Indiana. The church was built in 1858, and is a one-story, Greek Revival style frame building. It is sheathed in clapboard and has a gable roof. It features a projecting entrance tower added about 1900. The adjacent cemetery contains about 1,000 burials; the earliest marked burial was in 1823. Also on the property are the contributing shelter house and privy.It was listed on the National Register of Historic Places in 2005.