The 1963 Honduran coup d'état was a military takeover of the Honduran government on 3 October 1963, ten days before a scheduled election. Oswaldo López Arellano replaced Ramón Villeda Morales as president and initiated two decades of military rule.

Villeda Morales had instituted progressive labor laws and an agrarian reform policy, which prompted accusations of Communist sympathies from the right wing in Honduras and the United States. His intention to expropriate land from United Fruit Company, though never carried out, was a particular source of friction.

Civil–military relations in Honduras had deteriorated since 1957. A coup attempt in 1959, suppressed by students and unionist supporters of Villeda Morales, provoked intense hostility towards the military, as well as the creation of an autonomous presidential guard. Politicians discussed abolishing the military. Modesto Rodas Alvarado, the Liberal Party's candidate for president, ran on a demilitarization platform and was expected to win the election on 13 October 1963. The military acted pre-emptively and seized control of the government.