Oneida is an unincorporated community and former city in Oneida Township, Delaware County, Iowa, United States. The community is on county highway D13, south of Greeley.
A post office opened in Oneida in 1887 and operated until 1963. Oneida's population was 27 in 1902, and 127 in 1925.
Oneida was incorporated from May 29, 1912 until 1994.