Kaku is a Japanese surname and a masculine Japanese given name. Notable people with the name include:

Surname:

• Michio Kaku (加來 道雄, born 1947), American physicist
• Genji Kaku (郭 源治, born 1956), Taiwanese-born Japanese baseball player
• Tomohiro Kaku (郭 智博, born 1984), Japanese actor
• Kento Kaku (賀来 賢人, born 1987), Japanese actor
• Yuji Kaku (賀来ゆうじ), Japanese manga artist

Given name:

• Kaku Takagawa (高川 格, 1915–1986), Japanese Go player
• Kaku Takashina (高品 格, 1919–1994), Japanese actor