Born Leonid Molodozhanyn in Polonne, Russian Empire (now Ukraine), Mol learned the art of ceramics in his father's pottery workshop. Mol studied sculpture at the Leningrad Academy of Arts from 1936 to 1940.
Following the German invasion of the Soviet Union he was deported to Germany where he was influenced by Arno Breker. In 1945, he moved to The Hague, and in December, 1948, he and his wife, Margareth (whom he married in 1943), emigrated to Winnipeg, Manitoba. In 1949, he held his first ceramics exhibition in Winnipeg.
Mol was known for his sculptures of square dancers, skiers, aboriginals, and wildlife. Mol also completed more than 80 stained-glass windows in churches throughout Winnipeg.
More than three hundred of Mol's works are displayed in the 1.2 hectare Leo Mol Sculpture Garden in Winnipeg's Assiniboine Park which comprises a gallery, a renovated studio, and an outdoor display. The garden was unveiled on June 18, 1992 and has been expanded twice since. It is supported by private donations, and Mol personally donated 200 bronze sculptures to the city of Winnipeg. The sculptures are of religious leaders, prominent people, the human form, and wildlife.
Mol died July 4, 2009, at St. Boniface Hospital in Winnipeg, Manitoba. He was 94.