HMS G4 was a G-class submarine of the Royal Navy, built during the First World War. She was one of 14 submarines of her class, designed for coastal patrol and anti-submarine warfare.
Construction and Service:
- Builder: Chatham Dockyard
- Laid down: 16 October 1914
- Launched: 14 August 1915
- Commissioned: December 1915
Following her commissioning, HMS G4 served with the Royal Navy's home fleets, primarily conducting patrols in the North Sea. Her service life was relatively short, typical for many vessels during the intense naval warfare of the First World War.
Loss: HMS G4 was lost on 22 October 1918, just weeks before the armistice. She sank following a collision with the destroyer HMS Partridge off Harwich, England. All 26 members of her crew perished in the incident. The cause of the collision was attributed to a misunderstanding of signals in poor visibility.