Mimulus bolanderi is a species of monkeyflower known by the common name Bolander's monkeyflower. It is endemic to California, where it grows in the chaparral and other habitat in the coastal and inland mountains and foothills from the North Coast Ranges to the Sierra Nevada to the Transverse Ranges. This is a hairy annual herb producing an erect stem reaching maximum heights anywhere from 2 to 90 centimeters. The lance-shaped to oval leaves are up to 6 centimeters long and arranged in opposite pairs about the stem. The base of the flower is encapsulated by a hairy ribbed calyx of sepals with pointed lobes. The flower has a tubular throat and a wide, five-lobed mouth. It is 1 to 3 centimeters long and pink in color, usually with blotches of white in the throat.