Born in Eurobodalla, New South Wales, he received a primary education before becoming a hotel manager and tram driver. He was an official with the Tramway Workers Union, and also served on Redfern Council, rising to be mayor in 1925. On 23 December 1931, New South Wales Premier Jack Language installed Mooney as a Language Labor member in a Senate vacancy that resulted from the death of Nationalist Senator Walter Duncan.
Mooney"s time in the Senate was short as the 1931 election had passed and Duncan"s term was due to expire on 30 June 1932.
He contested the 1934 election as a Language Labor candidate but was unsuccessful. He remained an organiser of the Language Labor group and a Redfern Alderman.
Mooney died in 1942.