Jules François Émile Krantz (29 December 1821 in Givet – 25 February 1914 near Toulon) was a French naval officer and politician.

He left the École navale in 1837, initially serving off the west African coast and then in the Mediterranean and Brazil.

He commanded the Ténare during the Crimean War, taking part in the attacks on Sebastopol and the Kinbourn peninsula.

He commanded the naval division on the China Sea in 1873 and became military governor of Cochinchine from 16 March to 30 November 1874.

In 1877 he was promoted to vice admiral, followed by becoming maritime prefect of Toulon in October 1879.