The Commission de toponymie du Québec writes about it: “The name of this municipality of Saguenay, officially created in 1974, was borrowed from the river that flows there.

Without doubt, the proximity of Cape Eternity, which evokes the beyond, played a role in the choice of this name which alludes to the absence of beginning and end of the existence of God.

This name, in addition to identifying the post office established in 1933 and the parish of Notre-Dame-de-l'Éternité erected canonically in 1967, covers the municipality located between Saint-Félix-d'Otis and L'Anse-Saint-Jean.

The specific Eternity appears in documents written since at least 1824, according to the captain Louis Sivrac, and Arthur Buies [fr] indicates the cap Éternité, in 1880.

The Cap Trinité path which leads to the statue of Notre-Dame-du-Saguenay offers one of the best views of the fjord.