The Bitterroot Salish peoples (or Flathead, Salish, Séliš) are a Salish-speaking group of Native Americans, and one of three tribes of the Confederated Salish and Kootenai Tribes of the Flathead Nation in Montana. The Flathead Reservation is also home to the Kootenai and Pend d'Oreilles tribes. Bitterroot Salish Peoples or Flathead originally lived in an area west of Billings, Montana extending to the continental divide in the west and south of Great Falls, Montana extending to the Montana–Wyoming border. From there they later moved west into the Bitterroot Valley. By request, a Catholic mission was built there in 1841. In 1891 they were forcibly moved to the Flathead Reservation.

The Bitterroot Salish are known by various names including Salish, Selish, and Flathead. The name "Flathead" was a term used to identify any Native tribes who had practiced head flattening. The Salish, however, deny that their ancestors engaged in this practice. Instead, they believe that this name caught on because of their identifying sign in the Coast Salish Sign Language. Namely because it involved pressing both sides of the head with your hands, which meant 'we the people'.

The people are an Interior Salish group of Native Americans. They speak Salish, the namesake of the entire Salishan languages family. The Interior Salish group consists of the Flathead (Séliš), Kalispell (Qlispé) and Spokane

According to Salish history, the Salish speaking people originally lived as one large nation thousands of years ago. Their region stretched from Montana all the way to the Pacific Coast. Tribal elders say that the tribes started to break into smaller groups as the population became too big to sustain its needs in just one central location.

Following the dispersion the Salishan languages had branched into different dialects from various regions the tribes dispersed to. Centuries later, the separated groups of Salishan peoples became distinct and their corresponding languages had developed into the Salishan languag] family. The eastern sub-family family is known as Interior Salish. They consist of the Spokane language (npoqínišcn) spoken by the Spokane people, the Kalispel language (qlispé) spoken by the Pend d'Oreilles tribe, and the Bitterroot Salish (séliš) languages are all dialects of the same language.

The tribes' oral history tells of having been placed in their Indigenous homelands, which is now present-day Montana, from when Coyote killed the nałisqelixw, which literally translates into people-eaters.

Our story begins when the Creator put the animal people on this earth. He sent Coyote ahead as this world was full of evils and not yet fit for mankind. Coyote came with his brother Fox, to this big island, as the elders call this land, to free it of these evils. They were responsible for creating many geographical formations and providing good and special skills and knowledge for man to use. Coyote, however, left many faults such as greed, jealousy, hunger, envy, and many other imperfections that we know of today

— Clarence Woodcock