John Marcus Baddeley (20 November 1881 – 1 July 1953) was an Australian politician and member of the New South Wales Legislative Assembly from 25 March 1922 to 8 September 1949.

He was a councillor of Cessnock Shire from January until October 1914 and was the first president of the Australian Coal and Shale Employees' Federation from 1915 until 1922.

He was Secretary for Mines and Minister for Labour and Industry in the first (June 1925 to October 1927) and second Lang governments (November 1930 to May 1932).

[2] He was Deputy Premier, Colonial Secretary and Secretary for Mines in the McKell and McGirr governments from May 1941 until his retirement in September 1947, Minister for National Emergency Services from June 1944 to his retirement and Minister for Labour and Industry and Social Welfare from October 1947 to March 1948.

[1] Baddeley was chairman of State Coal Mine Authority from his retirement until his death of cerebrovascular disease at St Luke's Hospital in the Sydney suburb of Darlinghurst, survived by his wife, two sons and three daughters.