Cayoosh Mountain is a mountain summit located in the Cayoosh Range in southwestern British Columbia, Canada. It is situated east-northeast of Pemberton, north-northeast of Lillooet Lake, and immediately north of Cayoosh Pass. Its nearest higher peak is Mount Marriott, to the north-northeast. Precipitation runoff from the peak drains into Cayoosh Creek and other tributaries of the Fraser River. The mountain's name was submitted by Karl Ricker, a mountaineer, and was officially adopted on January 23, 1979, by the Geographical Names Board of Canada.