Lew Kowarski , born in 1907 with Saint-Pétersbourg in Russia, is a Physicien and Chimiste French.

He in particular worked as of 1934 with the Institut of radium with Frederic Joliot-Curie and Hans Halban on the fission of the Uranium, before fleeing in England in 1940 (Commission MAUD). He will then take part as a director of the Commissariat à l'Energie Atomique in the development of the nuclear French. He also took part in 1952 in the creation of CERN.

Since its retirement in 1972, it is devoted to teaching and is adviser near the the United Nations.