'Maundy I' was a British operation by the Special Operations Executive to intercept and destroy shipping in the Leads of German-occupied Norway (April 1941).

By a time early in March 1940, the SOE was training a mining squad, and on 29 April 1940 an initial Norwegian fishing boat left the Shetland islands group to lay mines in the Inner Leads, and ultimately 11 out of 18 mines provided by the Royal Navy were laid in Norwegian coastal waters.