HMS E19 was an E-class submarine of the Royal Navy, commissioned in 1914 at Vickers, Barrow-in-Furness. During World War I she was part of the British submarine flotilla in the Baltic. Under the command of Lieutenant Commander Francis Cromie, E19 was able to sink several German ships, most notably on the 11 October 1915 when she sank 4 German transport ships, just south of Öland, within a few hours and without any casualties. On 7 November 1915 E19 sank the German light cruiser SMS Undine.