Osoyoos (/ɒˈsuːjuːs/ o-SOO-ews, historically /ˈsuːjuːs/ SOO-ews) is a town in the southern part of the Okanagan Valley in British Columbia near the border with Washington state, between Penticton and Omak. The town is also adjacent to the Indian Reserve of the Osoyoos Indian Band. The origin of the name Osoyoos was the word suius meaning "narrowing of the waters" in the local Okanagan language (Syilx'tsn). The "O-" prefix is not indigenous in origin and was attached by settler-promoters wanting to harmonize the name with other O-names in the Okanagan Country (Oliver, Omak, Oroville, Okanogan).