He was born the oldest of four sons of Charles Machon Octoman (ca.1871 – 28 March 1949), perhaps in Tumby Bay, where his father, a coachbuilder, was a pioneer, or in Lipson, where he later had a farm.
[2] Dudley was employed as a teller with the National Bank of Australasia at Mount Gambier then Port Elliot[3] He enlisted with the RAAF during World War II and remained with the service for several years after cessation of hostilities.
He was elected to a Northern districts seat on the Legislative Council 6 March 1965 and died in office.
Dudley Octoman married Laurel Bond Riggs (1905–1990) on 1 March 1928.
He had three brothers: Frederick Joseph Reginald (15 December 1906 – 1992), born at Lipson SA, married Betty Hazel McDougall in 1933; a younger brother Vivian Machon Octoman (c. 1908–1967) who married Mavis Jessie Lorna Wishart in 1934, and the youngest Mervyn Provis Octoman (8 June 1911 – 1979) born at Port Lincoln, married (Doris) Violet Jean Wishart in 1936.