Rallia Christidou (Greek: Ραλλία Χρηστίδου, pronounced [raˈlia xrisˈtiðu]) is a Greek politician and a former singer. Christidou became known to the wider public through her participation in the television reality singing show Fame Story in 2004 where she took second place behind the winner Kalomoira. She then released eight albums between 2004 and 2013.

From 2011 and the outbreak of the economic crisis in Greece, Christidou began to participate in public life by joining the Greek political party Syriza, and in 2015 she was a Syriza candidate for member of parliament (MP) in the Athens B2 constituency of Athens. She was first elected MP with Syriza in the Athens B3 constituency in the 2019 parliamentary elections, and was re-elected in both the May 2023 and June 2023 parliamentary elections.

On 11 November 2024, during the elections for new leadership, Christidou announced her resignation from the party and her independence as an MP, denouncing the procedures followed for the election of a new party president. Since 24 November, she has been a member of the Movement for Democracy party and is a signatory to its founding declaration.