Mahonia nevinii (syn. Berberis nevinii, Odostemon nevinii), known by the common name Nevin's barberry, is a species of flowering shrub in the barberry family. This plant is endemic to southern California, where it is known from very few occurrences in the riparian areas of chaparral in inland canyons and foothills. It is a California state and United States federally listed endangered species, since 1987 and 1998, respectively. There are thought to be about 500 individuals remaining, with half of those being naturally occurring plants. It is also cultivated in gardens and parks as an ornamental and barrier plant.