The community of Chapleau was created as a divisional point during the construction of the Canadian Pacific Railway Transcontinental railway and was named for Joseph-Adolphe Chapleau.

The river begins at the north end of Chapleau Lake in Subury District, and flows north through Henderson Lake before taking in the left tributary Racine Creek.

it continues north to Schewabik Lake where it takes in the left tributary Swanson River.

It continues northeast, then north, takes in the left tributary Makonie River, enters Algoma District, and reaches its mouth at Kapuskasing Lake.

Chapleau-Nemegosenda River Provincial Park is a waterway park operated by Ontario Parks that includes the Chapleau River from the entry of the tributary Racine Creek to the river mouth at Kapuskasing Lake.