Yannis Markopoulos (Greek: Γιάννης Μαρκόπουλος; 18 March 1939 – 10 June 2023) was a Greek composer. In 1956 Markopoulos moved to Athens to further his music studies at the Athens Conservatoire under the composer Yiorgos Sklavos and the violin teacher Joseph Bustidui, while studying philosophy and sociology at the Panteion University.

While a student he composed music for the theatre, for the cinema and for dance performances. When he was 24 he was awarded the Music Prize of the International Thessaloniki Film Festival for Nikos Koundouros’ film Young Aphrodites and subsequently his works Theseus (dance-drama), Hiroshima (ballet suite) and Three Dance Sketches were performed by avant-garde dance groups. In 1967 a military dictatorship was imposed in Greece.