Osamu Yamasaki (山崎 理, Yamasaki Osamu, February 19, 1962) is a Japanese anime director, producer, director, and animator, born in Kumamoto prefecture. Yamasaki is a member and former director of the Japanese Animation Creators Association (JAniCA), and a member of the Directors Guild of Japan. He is part of Wao World.

He also works under his name written in katakana (ヤマサキオサム).