Papineau (formerly Papineau—Saint-Denis and Papineau—Saint-Michel) is a federal electoral district in Montreal, Quebec, Canada, that has been represented in the House of Commons of Canada from 1948 to 1988 and since 2004. Its population in 2006 was 101,019. Justin Trudeau, who is currently Prime Minister of Canada and Leader of the Liberal Party, has represented the riding since the 2008 federal election.

The name of the riding comes from a street in the Villeray neighbourhood, named after Joseph Papineau.

At nine square kilometres, it covers the second smallest area of any federal riding in Canada, after Toronto Centre. Linguistically, 45% of residents list French as their mother tongue, 8% list English, and 47% list neither English nor French, with large groups speaking Spanish, Italian, Greek and Arabic. The total immigrant population is 40 per cent.

The district includes the neighbourhoods of Villeray and Park Extension, and the southern part of the old city of Saint-Michel in the Borough of Villeray–Saint-Michel–Parc-Extension. The southeast corner of the riding borders the Outremont riding, which is held by Tom Mulcair, the leader of the New Democratic Party.

Papineau, despite its small size, is a very divided riding. The riding spans the former linguistic divide of the city, Saint Laurent Boulevard. South of the riding is the neighbourhood of Park Extension, which is very Liberal. The central part of the riding, around Villeray, was Bloc Québécois territory for almost two decades before swinging heavily to the NDP in the 2011 federal election. And François-Perreault district, in the south of Saint-Michel, is considered as swing territory between the Liberals and the NDP. The district of Saint-Michel, which is part of neighbouring Saint-Léonard—Saint-Michel riding to the northeast of Papineau, leans to the Liberals.

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