Hitoshi Iwaaki (Japanese: 岩明 均, Hepburn: Iwaaki Hitoshi; born July 28, 1960) is a Japanese manga artist, whose works include the science-fiction/horror series Parasyte.

During high school, he was reading a lot of manga by Osamu Tezuka, which inspired him to begin drawing manga himself. He began working as an assistant for manga artist Kazuo Kamimura in 1984. In 1985, his short story "Gomi no Umi" won the newcomer award Tetsuya Chiba Award and was published in a special edition of Morning magazine. Since then, he has worked mainly for Kodansha, especially Monthly Afternoon magazine.

In 1993, Iwaaki received the Kodansha Manga Award for Parasyte. In 2010, Historié took the grand prize in the manga division of the Japan Media Arts Festival. Historié also earned him the 2012 Tezuka Osamu Cultural Prize Grand Prize. Iwaaki won the 2020 Saito Takao Award for his work on Reiri.