Iwao (written: 巖, 巌, 岩夫, 岩尾, 岩生, 岩男 or 岩雄) is both a masculine Japanese given name and a Japanese surname. Notable people with the name include:

Surname

• Emma Haruka Iwao, Japanese computer scientist and cloud developer advocate
• Junko Iwao (岩男 潤子, born 1970), Japanese voice actress and singer
• Ken Iwao (岩尾 憲, born 1988), Japanese footballer
• Sachimi Iwao (岩尾 幸美, born 1976), Japanese field hockey player
• Seiichi Iwao (岩生 成一, 1900–1988), Japanese academic, historian and writer
• Sumiko Iwao (岩男 寿美子, 1935–2018), Japanese psychologist, magazine editor and academic

Given name

• Iwao Ageishi (上石 巌, 1908–1991), Japanese cross-country skier
• Iwao Akiyama (秋山 巌, 1921–2014), Japanese printmaker
• Iwao Ayusawa (鮎沢 巌, 1894–1972), Japanese diplomat
• Iwao Hakamada (袴田 巖, born 1936), Japanese boxer
• Iwao Horiuchi (堀内 岩雄, born 1941), Japanese sport wrestler
• Iwao Matsuda (松田 岩夫, born 1937), Japanese politician
• Iwao Matsuda (general) (松田 巌, 1895–1979), Japanese general
• Iwao Nakayama (中山 巌, born 1949), Japanese ice hockey player
• Ōyama Iwao (大山 巌, 1842–1916), Japanese field marshal
• Iwao Taka (高 巌), Japanese academic
• Iwao Takamoto (1925–2007), Japanese-American animator, television producer and film director
• Iwao Yamane (山根 巌, born 1976), Japanese footballer
• Iwao Yamawaki (山脇 巌, 1898–1987), Japanese photographer

Fictional characters

• Iwao (Kinnikuman) (イワオ), a character in the manga series Kinnikuman