Onomastus is a genus of Asian jumping spiders (family Salticidae) that was first described by Eugène Louis Simon in 1900.

[3] Onomastus species are delicate, translucent spiders, with long legs compared to most other members of the family Salticidae.

Males have highly complex, species specific palpal bulbs, which suggests rapid divergent evolution.

Two clades have been distinguished: in species from Southeast Asia, the palpal bulb has a broad conductor; in those from South Asia it has a medial branch on the median apophysis.

[2] Species of the South Asian clade are considered highly endangered due to habitat loss and climate change.