As of the 2016 Canadian Census, it had a population of 2,515;[1] while the First Nation's website reported a membership of 6,905 individuals as of December 2019.

Sandy Bay's original roots began after the signing of Treaty 1, in 1870 in Portage la Prairie, Manitoba.

In 1871, the Ojibway/French mixed-bloods, or "half-breeds", of the Portage Band requested a reservation be set aside for them.

While the request was accepted, the half-breeds were required "to move North, not nearer than 20 miles" where the current-day town of Westbourne is located.

Francois Demarais won and became the first elected Chief, with Baptiste Spence and Wah-sah-hook winning for the first-ever councilor positions.