Iconoclast is a New York avant jazz duo consisting of Julie Joslyn (alto saxophone, live electronics, violin, vocals) and Leo Ciesa (drums, percussion, keyboards, vocals). Iconoclast has been performing and recording since 1987 and has released ten studio albums, and is featured in All About Jazz.

The duo has received an Artist's Fellowship in Music Composition from the New York Foundation for the Arts as well as grants from Meet the Composer and from Arts International: The Fund for U.S. Artists at International Festivals and Exhibitions, now known as Mid Atlantic Arts Foundation: US Artists International.

Iconoclast has performed at festivals in The United States, Canada, Italy, Poland, Hungary, Serbia, Czech Republic, and Slovenia. The duo performed regularly beginning in 1988 at the New York clubs CBGB and the Knitting Factory. Iconoclast collaborated and performed with Polish poet Andrzej Dorobek (pl).