Lake Louisa (French: Lac Louisa) is a lake located in the Argenteuil region of Quebec, Canada, mostly in the Township of Wentworth.

[1] However, the southwestern part of the lake is located in the Les Pays-d'en-Haut region of Quebec.

[2] The maximal depth of the lake is 56.6 m, according to a 2011 GPS survey.

The town has a church called St. Aidan's and a community center for resident to rent.

A social club on the lake runs activities such as swimming lessons in summer months, and a property owner's association is active on the lake to manage the impact of human activities on the lake's health.