Johnny Hallyday (Jean-Philippe Léo Smet, b. 15 June 1943 in Paris – d. 6 December 2017, in Marnes-la-Coquette) was a French singer and actor. Influenced by Elvis Presley and the 1950s rock 'n' roll revolution, Hallyday became famous in the 1960s for singing rock 'n' roll in French.

Hallyday's father, Léon Smet (1908–1989), was Belgian; his mother, Huguette Clerc (1920–2007), was French. Born in Paris, Hallyday took his stage name from his aunt Desta's husband and dance partner Lee Hallyday