Hirioshi Watanabe (b. 1951) is a Japanese artist based in California.
Born in Sapporo, Hokkaido, Japan, Watanabe graduated from Nihon University in 1975 and received an MBA from UCLA in 1993. His first published collection was I See Angles Every Day (2007), depicting portraits of patients and scenes from San Lázaro psychiatric hospital in Quito, Ecuador. In 2009, Watanabe received a commission from the San Jose, California Museum of Art to document his perspective of the city’s Japantown. The work centered around artifacts from the Japanese internment camps established during WWII. He has since shown work in North Korea, Italy, North Carolina and Oregon. Watanabe won a Critical Mass Award from Photolucida in 2006 and received a grant from the Pollock-Kasner Foundation in in 2016.