Maslyn Williams moved to Australia in the 1920s. He grew up on New South Wales rural properties in the New England and Southern Highlands districts after the death of both parents. Williams initially studied music at the Conservatorium in Sydney before turning to journalism and radio scriptwriting. He joined National Studios in 1935 where he was assistant to Frank Coffey, editor of the Charles Chauvel film, Uncivilised (1936). After the Studio closed in 1938, Williams joined the Commonwealth Government's Cinema and Photographic Branch, the first government filmmaking unit.
The Department of Information (DOI) formed in September 1939 took over the Cinema and Photographic Branch; Williams became a war correspondent working for the Middle East Unit of the DOI under Frank Hurley. The Unit covered the war in the Middle East with footage supplied to Cinesound and Movietone. After the war, Williams joined the Film Division, DOI as a senior producer. Williams belonged to the 'art form stream, the stream that was culturally oriented' and sought to imbue his work with a more personal approach focused on individuals. He is best remembered for his docudrama, Mike and Stefani (1952).
Williams became Head of the PNG Division of the Film Unit from 1955, producing a series of films on Papua New Guinea. He left the Unit in 1962, unhappy with the constraints, and concentrated on writing books on China, Cambodia, Papua New Guinea and Indonesia.
Williams also wrote The East Is Red (1967), The Land In Between : The Cambodian Dilemma (1969), In One Lifetime (1970), a study of Papua New Guinea, The Story of Indonesia (1976), Faces of My Neighbour : Three Journeys into East Asia (1979) and The Phosphateers: A History of the British Phosphate Commissioners and the Christmas Island Phosphate Commission (1985) .