Jean Cosmovici is the son of Leon C. Cosmovici, professor at the University of Iași.

He was born on January 6, 1888 in Iasi. He attended primary school and high school in Iasi (National High School) between 1894-1898 and 1898-1906. He was a cousin of George Enescu, which initially led him to enroll in the Conservatory.

He studied at the School of Fine Arts in Iași (1911) and at the Academy of Fine Arts (Académie d`Arts Plastiques) in Paris, France, where he had as teachers Emanoil Bardasare, Jean Paul Laurens, Lagrouillere, Leregretiere.

In 1908 he returned to the country and enrolled in the second year at the School of Fine Arts, which he finished in 1911. He had his first exhibition with O. Briese. Win the Leconte du Noüy competition. In 1913 he left for Paris. He also enrolls in the Faculty of Law. In 1914 he returned to the country. He participated in the Official Salon (1915) and fought in the war (1916-1918).

He was appointed professor (1918) and custodian of the Art Gallery (1919). He also enrolled at the Faculty of Letters and Philosophy. He is appointed director of the Art Gallery. He is appointed professor at the Higher School of Fine Arts. Since 1908 he has had one or two exhibitions every year, in Iasi, Bucharest, Chisinau, Chernivtsi, Lugoj. He also participated in the Official Salon in Paris (1925-1938).

He made static natures with landscapes, flowers, portraits. It oscillated between Impressionism and Jugendstil. He preferred the intense colors of blue. Good cartoonist. He worked a lot in gouache. He was influenced by Tonitza.

C. Baba, Șt.Vlădescu, Cezar Horea, N.Tonitza, P.Comarnescu, Tache Soroceanu etc. wrote about him.

He was a member of the Association of Moldovan Writers and Artists (1930). Jean Leon Cosmovici was appointed professor at the Academy of Fine Arts in Iași in 1931 and director of the Pinacoteca in Iași in 1934.

He died on July 2, 1952 in Bucharest and was reburied in Iasi in 1959.