Captain John Catterall Leach, DSO, MVO (1 September 1894 – 10 December 1941) was a British naval officer.

Very soon after Prince of Wales entered active service in 1941, the ship fought under Leach's command in the Battle of the Denmark Strait, and suffered damage fighting the German battleship Bismarck.

However, damage inflicted by Prince of Wales caused Bismarck to lose fuel, forcing the latter to attempt to return to a base in occupied France.

[1] Despite a proposal to court-martial Leach for breaking off the action with Bismarck after Hood had sunk,[2][3][Note 1] he was awarded the Distinguished Service Order for his part.

[6] His son was Admiral of the Fleet Sir Henry Leach (1923–2011), who was First Sea Lord during the Falklands War.