- Mathew Aloysius Stackpool is killed in action at Gallipoli
- The first Victoria Cross is awarded at Gallipoli. British stretcher-bearer Lance-Corporal Walter Parker braves heavy machine gun fire to carry water, medical supplies and ammunition to an isolated forward position. He evacuates the wounded, despite being seriously injured himself.
- The German submarine U-30 torpedoes the American merchant ship SS Gulflight, in the Mediterranean Sea near Sicily. The attack comes without prior warning as the Gulfight transports a load of petroleum from Texas to Rouen in France. Fearing that the vessel will sink, all but two of the 38 crew safely evacuate to patrol vessels; their captain suffers a fatal heart attack en route to port.
- The International Congress of Women concludes at The Hague. The congress resolves that international disputes should be handled by pacific means, with women given equal political rights, most importantly, the right to vote. A process of continuous mediation to restore peace is called for, encompassing international cooperation, general disarmament, national self-determination and the creation of a Society of Nations. Resolutions are printed in English, French and German and distributed to European heads of state in early May 1915.