Harry B. Lachman (June 29, 1886 – March 19, 1975) was an American artist, set designer, and film director.

He was born in La Salle, Illinois on June 29, 1886. Lachman was educated at the University of Michigan before becoming a magazine and book illustrator, contributing 4 colour illustrations to the 1907 work John Smith, Gentleman Adventurer by Charles Harcourt Ainslie Forbes-Lindsay. In 1911, he emigrated to Paris where he earned a substantial reputation as a post impressionist painter and was awarded the Légion d'Honneur by the French government.

Lachman's interest in motion pictures stemmed from his position as a set designer in Nice, leading to work on Mare Nostrum in 1925. He worked as a director in France and England before settling in Hollywood in 1933. His credits include Down Our Street, Baby Take a Bow, Dante's Inferno, Our Relations, and Dr. Renault's Secret.

In 1938 he married Jue Quon Tai. Lachman returned to painting in the 1940s. He died on March 19, 1975.