Six-year-old Lee Allan Bonneau was found Wednesday in a wooded area with serious injuries on Kahkewistahaw (kack-ah-WISH-tah-haw) First Nation, east of Regina.
He had been reported missing a couple of hours after being spotted playing with dogs outside the band's community centre, where people had gathered for bingo.
Searchers later found the child about two blocks away from the hall and he was rushed to hospital, where he died of his injuries.
RCMP say his wounds were consistent with an assault.
They say they are talking with residents and trying to piece together the last hours of the boy's life.