Jonathan Martin "Jon" Isaacs (born 10 September 1949) is a former Australian politician. He was the Labor member for Millner in the Northern Territory Legislative Assembly from 1977 to 1981, and was the ALP's first leader in that body and the Territory's first Opposition Leader.
The Electorate of Millner was named after Dr James Millner, the medical officer in Goyder's 1869 expedition to found the first colony at Port Darwin, who drowned in the SS Gothenburg tragedy.