One party or one-party state may refer to:
One-party state, a state in which a single political party controls the ruling system One-party government, a government formed in a multi-party state that consists exclusively of representatives of one party The ONE Party, a political party in New Zealand In law, a party to a legal action or contract In United States telephone call recording law, a one-party consent state One Party State (album), a 2010 album
See also Dominant-party system Party Party system Political party