Joseph O'Neill or O'Neil may refer to:
Joseph O'Neill (writer, born 1964), Irish-born novelist and author of Netherland Joseph O'Neill (writer, born 1886) (1886–1953), Irish novelist Joseph O'Neill (politician), Irish politician, member of the 14th Seanad Joseph P. O'Neill (born 1947), American Democratic Party strategist in Washington, D.C. Joe O'Neill (born 1982), English footballer Joseph H. O'Neil (1853–1935), U.S. Representative Joseph P. O'Neil (1863-1938), U.S. Army general Joseph T. O'Neill (1931-2022), American lawyer and politician
See also Joseph T. O'Neal (1881–1944), American politician; mayor of Louisville, Kentucky