Oton Postružnik (1900-1978) was a Croatian artist, painter, graphic artist, and ceramist.
He was one of the founding members of the Earth Group artist collective in Zagreb from 1929-1933.
He studied in Zagreb, Prague and Paris, and was a professor at the Academy of Fine Arts in Zagreb from 1950-1970.
He is best known for his abstract paintings of natural subjects, such as his Leaf series.
Oton Postružnik received the Vladimir Nazor Award for lifetime achievement in 1964.