Joëlle Léandre (born 12 September 1951) is a French double bassist, vocalist, and composer active in new music and free improvisation.

In the field of contemporary music, she has performed with Pierre Boulez's Ensemble InterContemporain, and worked with Merce Cunningham and John Cage. Both Cage and Giacinto Scelsi have composed works specifically for her.

She gave a solo concert at Jazz em Agosto in 2007 (Calouste Gulbenkian Foundation, Lisbon, Portugal). At this same jazz festival, Léandre also performed in the Quartet Noir, a quartet which rarely performed live, with Marilyn Crispell, Urs Leimgruber and Fritz Hauser.

She has also collaborated with musicians in the fields of jazz and improvised music, including Derek Bailey, Barre Phillips, Anthony Braxton, George E. Lewis, India Cooke, Evan Parker, Irène Schweizer, Steve Lacy, Maggie Nicols, Fred Frith, Vinny Golia, Carlos Zingaro, John Zorn, Susie Ibarra, J. D. Parran, Kevin Norton, Eric Watson, Ernst Reijseger, Akosh S. and Sylvie Courvoisier.

In 1983 she became a member of the European Women Improvising Group (EWIG), which evolved from the Feminist Improvising Group, and in the early 1990s she co-founded the feminist improvising trio Les Diaboliques, with Schweizer and Nicols.