Matsu or Mazu can refer to:

• Matsu Islands, are islands of the Republic of China located off the southeastern coast of the People's Republic of China.
• Matsu, a significant sea goddess in Chinese culture.
• Mazu Daoyi (馬祖道一; also written Matsu Tao-i) was an influential Zen teacher in medieval China.
• Matsu, a book by Osamu Dazai
• Mazu footwear
• Mazu_Networks Producer of "Mazu Profiler" and "Mazu Enforcer" - anti-hacking tools