Ivan Ilyich Leonidov (Russian: Иван Ильич Леонидов; 9 February 1902 – 6 November 1959) was a Soviet constructivist architect, urban planner, painter and teacher.

From 1921 to 1927 he studied at the VKhUTEMAS in Moscow under the tutelage of Alexander Vesnin at which point his attention switched from painting to architecture.

His unexecuted diploma project in 1927 for the Lenin Institute and Library, Moscow, brought him international recognition.

The scheme was prominently displayed at the Exhibition of Contemporary Architecture, Moscow, and was published in the OSA Group journal Sovremennaya arkhitektura.

From 1931 to 1933 he worked in the Giprogor Russian Institute of Urban and Investment Development and Mossoviet and from 1934–41 he joined the studio of Moisei Ginzburg at the People's Commissariat for heavy industry.