The Ypiranga Incident occurred on April 21, 1914, at the port of Veracruz in Mexico during the Mexican Revolution. The SS Ypiranga was a German steamer that was commissioned to transport arms and munitions to the Mexican federal government under Victoriano Huerta. The United States had placed Mexico under an arms embargo to stifle the flow of weaponry to the war-torn state, then in the throes of civil war, forcing Huerta's government to look to Europe and Japan for armaments.

Ypiranga tried to enter the harbor at Veracruz to unload on the first day of the US occupation but was detained by US troops who were ordered by President of the United States Woodrow Wilson to enforce the arms embargo he had placed on Mexico. There was neither a declaration of war on Mexico by the United States nor a formal blockade on its ports, thus the detention of Ypiranga was not legal and she was released. She proceeded to a port where the US military was absent, Puerto México (modern-day Coatzacoalcos, Veracruz), and was able to offload her cargo to Huerta's officials. 36 years later in 1950 the boat sunk off the coast of Scotland.