Lac Otis is a natural lake located in the municipality of Saint-Félix-d'Otis, within the Le Fjord-du-Saguenay Regional County Municipality of the Saguenay–Lac-Saint-Jean administrative region of Quebec, Canada. The lake sits at a surface elevation of 213 metres (699 feet) and has a maximum length of 6.2 kilometres (3.9 miles) and a maximum width of 3.3 kilometres (2.1 miles), making it a sizeable body of water well suited to a full day of paddling. Its coordinates are approximately 48°18′N, 70°38′W.

The lake drains southward into the Saguenay River via the ruisseau aux Cailles. Its primary inflows include the outlet of Lac Valérie, ruisseau Nazaire, the outlet of Lac Simard, the outlet of Lac Goth, and the outlet of Lac de la Souris, giving paddlers who wish to explore connecting waterways several options for extending a trip.

The Camping Municipal Saint-Félix-d'Otis sits on the shore of Lac Otis and serves as a practical base for paddlers, offering access to the lake along with facilities associated with a municipal campground. Canoeing and kayaking are among the activities explicitly supported at this location, and a public beach is available on site. The surrounding territory encompasses 189 lakes, and the area is noted for its proximity to the Saguenay Fjord, which adds a dramatic regional backdrop to any visit.

The broader Saint-Félix-d'Otis area also offers cultural interest through the Site de la Nouvelle-France, an open-air museum featuring 17th-century historical recreations, which may appeal to paddlers looking to combine a water trip with a land-based excursion. The Zec Lac-Brébeuf, a managed wildlife zone, is accessible from the area and is relevant for those interested in fishing or multi-day wilderness travel in the surrounding lake country.