Jean Castex (French: [ʒɑ̃ kastɛks]; born 25 June 1965) is a French politician who served as Prime Minister of France from 3 July 2020 to 16 May 2022. He was a member of The Republicans (LR) until 2020, when he joined La République En Marche! (LREM). Castex served for twelve years as mayor of the small town of Prades prior to his appointment as prime minister by President Emmanuel Macron. He resigned his post ahead of the 2022 legislative election. He has been president of the state-owned RATP since November 2022.