The May Fourth Movement (Wusi Yundong) was an anti-imperialist, cultural, and political movement growing out of student demonstrations in Beijing on May 4, 1919, protesting the Chinese government's weak response to the Treaty of Versailles, especially the Shandong Problem. These demonstrations sparked national protests and marked the upsurge of Chinese nationalism, a shift towards political mobilization and away from cultural activities, and a move towards a populist base rather than intellectual elites.

The broader use of the term 'May Fourth Movement' often refers to the period during 1915-1921 more usually called the New Culture Movement.