Pedro Aznar (born 23 July 1959) is an Argentine musician and singer-songwriter. He has a musical experience in jazz, Argentine folk and rock music and has a successful career as a solo artist. He is well known for giving rock songs a jazz-oriented style, by playing the fretless bass, with a big influence from Jaco Pastorius.

Is a multi-instrumentalist and the author of several books of poetry published in Argentina. He plays an important part in Argentine rock, where in the mid-1970s, he had various appearances with groups like Madre Atómica, ALAS and Pastoral. He became one of four members of Serú Girán in 1978, one of the most musically influential bands that dominated Argentina's rock circuit for the next four years. In 1982 he accepted an invitation from Pat Metheny to join The Pat Metheny Group as a vocalist, with whom he recorded three Grammy Award-winning albums.