Mosiondz Lev Yakovlevich (1909, Łódź, Poland — unknown) — design engineer.

From 1925 to 1929 Lev Mosiondz worked in a bookbinding workshop in the city of Gorky. From 1929 to 1931 he was employed as a bookbinder at the enterprise Nizhpolograf. From 1931 to 1934 he studied at the Baranov Aviation Technical School. After graduating from the technical school, he was employed as a design engineer at the Radiotelephone Plant.

From 1936 to 1938 he worked as a design engineer at the Metallurgical Plant named after M. Kaganovich. From 1938 to 1943 he was a design engineer at the Krasny Yakor (“Red Anchor”) Plant. From 1943 to 1945 he served in the ranks of the Red Army.

In 1946 he returned to the city of Gorky and worked as a design engineer at the Molotov Automobile Plant. In 1948 he moved to Riga, where he worked as a design engineer at the Riga Carriage Works. From 1965 he was employed at the Riga Jewelry Factory.