The Sainte-Marguerite Bay is a body of water located on the Saguenay River, at the confluence of the Sainte-Marguerite, in the municipality of Sacré-Cœur, in the regional county municipality (RCM) of La Haute-Côte-Nord, in the administrative region of Côte-Nord, Quebec, Canada.

The bay lies opposite Cap de l'Anse au Cheval (on the south shore of the Saguenay River).

The entrance to the bay is located between two 320 m-high rocky capes, including Cap Sainte-Marguerite (on the south side).

[2] Sainte-Marguerite Bay is characterized by stony, sandy shoals that appear at low tide.

[3][note 1] The toponym “Sainte-Marguerite Bay” was officialized on December 5, 1968, in the Place Name Bank of the Commission de toponymie du Québec.