[15][16][17] Québec solidaire was founded on 4 February 2006 in Montreal by the merger of the left-wing party Union des forces progressistes (UFP) and the alter-globalization political movement Option Citoyenne, led by Françoise David.

[19] Québec solidaire's first political venture was to field a candidate, Manon Massé, in a 10 April 2006 by-election in Sainte-Marie–Saint-Jacques.

They were also endorsed by the Montreal Central Council of the Confédération des syndicats nationaux which represents 125,000 members in Quebec.

[21] He won his seat for the second term in the 2012 election along with another QS candidate Françoise David in the Montreal riding of Gouin.

Subsequently, Khadir stepped down as co-spokesperson in accordance with QS party rules that stipulate one spokesperson must be from outside the legislature.

On 19 January 2017, Françoise David announced her immediate retirement as both party spokesperson and as a Member of the National Assembly due to her health.

[30] Massé brought attention to the QS due to her "unconventional" performance in the debates where she used simple, blunt language.

[35] On 16 May 2021, Massé announced she would hand the parliamentary leadership role to Nadeau-Dubois, and that he would be the party's candidate for premier in the upcoming 2022 election.

On 13 March 2023, Québec Solidaire won a 12th seat in the Saint-Henri-Sainte-Anne by-election, vacated by former Liberal leader Dominique Anglade.

[37] On November 26, 2023, Émilise Lessard-Therrien was elected co-spokesperson of Québec Solidaire at the party congress in Gatineau, defeating Ruba Ghazal and Christine Labrie.

[41][42] In addition to advocating the independence of Quebec from Canada, the party's platform identifies with the concepts of environmentalism, feminism, social justice, proportional representation and participatory democracy, pacifism, aboriginal rights, and alter-globalism.

[43] The party also favours immigration, human dignity, and opposes discrimination including racism, sexism, and homophobia.

The party leadership is assumed by the National Coordinating Committee, composed of 16 persons elected by the founding congress.

[22] The national spokespersons have greater visibility than the secretary general and are best known; they are sometimes referred to in the media as the de facto co-leaders of the party.

Students and staff at institutions of higher education are grouped in campus associations that also participate in the democratic life of the party.

The National Commission for Women is composed of delegates from each region and is responsible for ensuring that feminism is a value which transverses the party.