The Rivière du Lièvre (known in Algonquin as Okai Sipi, meaning "Hare River") is a major tributary of the Ottawa River in Quebec, flowing roughly north to south along approximately longitude -75.5 for a total length of 330 kilometres. Its drainage basin covers 9,542 km², and it originates at Lac Orthès before passing through communities including Ferme-Neuve, Mont-Laurier, Notre-Dame-de-Pontmain, Notre-Dame-du-Laus, Val-des-Bois, Notre-Dame-de-la-Salette, L'Ange-Gardien, and Gatineau, where it meets the Ottawa River. The river spans both the Laurentides and Outaouais administrative regions.

The upper stretches of the river are characterized by clear water and a relatively gentle current, making them well suited to day trips and shorter excursions. The lower sections, as the river approaches its confluence with the Ottawa, become broader and more dynamic, with a mix of calm stretches and mild rapids. A notable whitewater section exists within the territory of ZEC Normandie, where multi-day canoe trips are possible; this area has historically been used for six-day expeditions covering roughly 68 kilometres of river. Paddlers planning trips in the ZEC Normandie area should contact the ZEC directly, as access fees and permits apply.

At the downstream end of the river in Gatineau, the Centre Nautique de la Lièvre operates at 255 Avenue de Buckingham and provides access to approximately 18 kilometres of navigable flat water. The centre offers rentals of kayaks, canoes, paddleboards, and pedal boats, along with introductory courses and paddleboard yoga. It typically operates from late June through early September. Facilities on site include a welcome pavilion, picnic tables, potable water, and washrooms.

In Val-des-Bois, there is a boat launch with parking that provides easy river access, primarily used by anglers targeting northern pike and walleye. The river falls under fishing Zone 10 for regulatory purposes, with some tributary sections subject to Zone 29 rules; paddlers who fish should verify current regulations with Quebec's wildlife authority before their trip.