Ivan Picelj (28 July 1924 – 22 February 2011) was a contemporary Croatian painter, sculptor and graphic designer.

The multiplication of the basic plastic unit within a regular grid is one of his trademark procedures.

He was one of the founders and members of the group EXAT 51 which, in the period 1950–1956, consisted of the architects Vjenceslav Richter, Bernardo Bernardi, Zdravko Bregovac, Božidar Rašica and Vladimir Zaharović, and the painters Vlado Kristl and Aleksandar Srnec.

He spent a lot of time in Paris where he collaborated with the Denise René Gallery.

He exhibited at many solo (since 1952) and group shows, such as the Venice Biennale (1969, 1972), A Century of Avant-garde Art in Middle and Eastern Europe (Bonn, 1994), Constructivism and Kinetic Art (Zagreb, 1995), Ivan Picelj – Graphic Art Opus 1957–2003, International Centre of Graphic Arts (MGLC), (Ljubljana, 2003), Picelj, Denise René Gallery (Rive Gauche, Paris, 2008).