John Leighton Nanson (22 September 1863 – 29 February 1916) was a journalist and politician in Western Australia.
A former writer and sub-editor with The West Australian, he served in the Legislative Assembly of Western Australia from 1901 to 1905 and again from 1908 to 1914.
Nanson was a minister in the governments of Alf Morgans, Walter James, Newton Moore, and Frank Wilson, including as attorney-general from 1909 to 1911.