He was educated at Scotch College, Melbourne[2] and joined the State Bank of Victoria in 1866 and worked in various country branches.

He resigned as secretary in 1893 to become managing director of the Mount Lyell Mining & Railway Company, but was immediately appointed to BHP's board, a position he retained until 1910.

[1] He supported the federation of Australia and was elected as the first member for Kooyong at the inaugural 1901 election, initially as a member of the Free Trade Party, although he later supported some of the protectionist policies of the Protectionist Party.

Knox was responsible for moving a motion to begin each sitting day with prayers.

[3] Knox was also one of the seven members of the Prahran & Malvern Tramways Trust, established in 1908 to build part of Melbourne's electric tram network.