Matsu may refer to:
- Matsu Islands, islands of the Republic of China
- Matsu (goddess), a sea goddess in Chinese folk religion
- Matsu, a book by Osamu Dazai
- Matanuska-Susitna Valley, an area in south-central Alaska
- Matsu, a Japanese World War II destroyer
- Matsu class destroyer
- Japanese submarine I-29, code-named Matsu
For the realities of Chinese origin see Mazu