Artemios "Demis" Ventouris-Roussos was a Greek singer, songwriter and musician. As a band member, he is best remembered for his work in the progressive rock music act Aphrodite's Child, but as a vocal soloist, his repertoire included hit songs like "Goodbye, My Love, Goodbye", "From Souvenirs to Souvenirs" and "Forever and Ever".

Aphrodite's Child was a Greek rock and pop band formed in 1967, by Evangelos Papathanassiou, later known professionally as Vangelis,, Demis Roussos, Loukas Sideras, and Silver Koulouris (guitar). They initially found success in Europe with hit singles like "Rain and Tears", "End of the World", "I Want to Live", and "It's Five O'Clock", before pivoting to progressive rock with their third and final album, 666 (1972). An ambitious concept album inspired by the Book of Revelation, it later gained critical acclaim and has appeared on a number of lists of the top progressive and psychedelic albums of all time.