Timarcha is a genus of leaf beetles in the family Chrysomelidae, with more than 100 described species in three subgenera.

The most widely known species is T. tenebricosa, the bloody-nosed beetle.

All species are black, wingless organisms.

Timarcha are herbivorous species, living mostly on plants belonging to Rubiaceae and Plumbaginaceae, although a few can feed on Brassicaceae and Rosaceae.

These 20 species belong to the genus Timarcha: Data sources: i = ITIS,[2] c = Catalogue of Life,[3] g = GBIF,[4] b = Bugguide.net[5]