Pedro Aznar (born 23 July 1959) is an Argentine musician, with a lifetime of experience in jazz, Argentine folk music, and rock and has had a successful career as a solo artist. He is very well known for giving rock songs a jazz-oriented style, by playing the fretless bass, with a big influence from Jaco Pastorius. He is a multi-instrumentalist and the author of several books of poetry published in Argentina.

He is also an important figure in Argentine rock, where in the mid-1970s, he had various appearances with groups like 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.