Iosif Samuilovich Shklovsky (Russian: ??´??? ?????´????? ????´?????; sometimes transliterated Josif, Josif, Shklovskii, Shklovskij) (1 July 1916 – 3 March 1985) was a Soviet astronomer and astrophysicist.
He is remembered for work in theoretical astrophysics and other topics, as well as for his 1962 book on extraterrestrial life, the revised and expanded version of which was co-authored by American astronomer Carl Sagan in 1966 as Intelligent Life in the Universe.
He won the Lenin Prize in 1960 and the Bruce Medal in 1972.
Asteroid 2849 Shklovskij and the crater Shklovsky (on the Martian moon Phobos) are named in his honor.
He was a Corresponding Member of Soviet Academy of Sciences since 1966.