Lac-Saint-Jean-Est (French pronunciation: [lak sɛ̃ ʒɑ̃ ɛst]) is a regional county municipality in the Saguenay–Lac-Saint-Jean region of Quebec, Canada.

The seat is Alma.

In 2016, 99.3% reported that they spoke French most often at home, according to the census.

[3] There are 18 subdivisions within the RCM:[2]

Highways and numbered routes that run through the municipality, including external routes that start or finish at the county border:[8]