Fadden was born in Ingham, Queensland, to Irish immigrant parents. He was raised in Walkerston, and left school at the age of 15. He was appointed town clerk of Mackay in 1916, but following the 1918 cyclone moved to Townsville and opened an accountancy firm. He was elected to the Townsville City Council in 1930, and in 1932 was elected to the Queensland Legislative Assembly for the Country and Progressive National Party. Fadden lost his seat in 1935, but the following year won a by-election to the federal Division of Darling Downs.