In socialist party politics, a tendency is a political faction, usually within a Marxist party or a Marxist faction of a wider party.

Examples include:

• Debs Tendency, a group formed around Eugene Debs in the Socialist Party USA
• International Marxist Tendency, the former name of the Revolutionary Communist International
• International Socialist Tendency, a coalition of Trotskyist organizations espousing the ideas of Tony Cliff
• Johnson–Forest Tendency, a Trotskyist group in the Workers Party (1940–1949) of the United States
• Marxist Tendency, a Trotskyist organization in post-Soviet Russia
• Militant tendency, a Trotskyist group in the UK Labour Party in the 1980s
• Militant Tendency (Ireland), a Trotskyist group that became the Irish Socialist Party
• Pathfinder tendency, a group of organizations that cooperate with the Socialist Workers Party of the United States