LEAK is the brand name for high-fidelity audio equipment made by H. J. Leak & Co. Ltd, of London, England. The company was founded in 1934 by Harold Joseph Leak and was sold to the Rank Organisation in January 1969. During the 1950s and 60s, the company produced high-quality amplifiers, radio tuners, loudspeakers (the LEAK Sandwich), pickups, arms and a turntable. The sale of the business to Rank saw an expanded range of models, and considerable further development of loudspeakers, but Rank was not able to position the brand to counter competition from Japanese electronics manufacturers, so by the late 1970s electronics and speaker production ceased under the LEAK name.

A leak is a way (usually an opening) for fluid to escape a container or fluid-containing system, such as a tank or a ship's hull, through which the contents of the container can escape or outside matter can enter the container. Leaks are usually unintended and therefore undesired. The word leak usually refers to a gradual loss; a sudden loss is usually called a spill.

In the folklore of Bali, the Leyak (in Indonesian, people called it 'Leak' (le-ak)—the Y is not written or spoken) is a mythological figure in the form of flying head with entrails (heart, lung, liver, etc.) still attached. Leyak is said to fly trying to find a pregnant woman in order to suck her baby's blood or a newborn child. There are three legendary Leyak, two females and one male.