Lac-Sergent (French pronunciation: [lak sɛʁʒɑ̃]) is a village situated alongshore Sergent Lake in Portneuf Regional County Municipality in the Canadian province of Quebec.

It is about 50 kilometres (31 mi) north-west of Quebec City.

In the 2021 Census of Population conducted by Statistics Canada, Lac-Sergent had a population of 541 living in 263 of its 432 total private dwellings, a change of 8.9% from its 2016 population of 497.

With a land area of 3.72 km2 (1.44 sq mi), it had a population density of 145.4/km2 (376.7/sq mi) in 2021.

[4] Population trend:[5] Mother tongue: