HMS Slinger was an experimental catapult ship operated by the Royal Navy during the First World War.

Constructed as a hopper barge, HMS Slinger was purchased from her builder, Lobnitz and Company, Limited of Renfrew, Scotland, prior to completion.

Intending to use her as a test bed for the shipborne launching of aircraft, the Royal Navy fitted her with a 60-foot (18.25-meter) compressed air catapult.

She entered commercial service under the Greek flag with Boyazides L, Brother & Company in 1920 as SS Niki.

Lingfield continued to operate as a commercial cargo ship until 17 October 1941, when she collided with another vessel in the North Sea off the coast of Norfolk, England, and sank.