Abudefduf, also known as the sergeant-majors, is a genus of fish in the family Pomacentridae.

The name is from Arabic abu, "the one with"; and def, "side", and the intensive plural ending -duf.

[2] The approximately 20 species of Abudefduf may be divided into planktivores and benthivores and three broadly pantropical clades.

Most diversification has occurred in the last 10 million years within this genus across all clades.

[6][7] The following 21 species are recognized in the genus Abudefduf:[8]