Sir Bernard Katz, FRS was a German-born British physician and biophysicist, noted for his work on nerve physiology; specifically, for his work on synaptic transmission at the nerve-muscle junction. He shared the Nobel Prize in physiology or medicine in 1970 with Julius Axelrod and Ulf von Euler. He was made a Knight Bachelor in 1969.

A neuromuscular junction is a chemical synapse between a motor neuron and a muscle fiber.