Cyril James Morton was born at Wanganui on 19 April 1903, the son of Helen Molloy and her husband, William Thomas James Morton, a grocer. He was educated at South Wellington School and Wellington College. After leaving school he worked as an office boy at a film distribution company. This, and his hobby of photography, led to his being offered a job by Frank Stewart at New Zealand Films Limited, a small film-making company. There Morton learned about the technical aspects of film-making, and gained experience as a cinematographer. He helped to film the prince of Wales's tour in 1920, and worked on The slums of Wellington (1920) and other films.
Morton joined the government's Publicity Office as a cinematographer in 1923. He travelled throughout New Zealand filming the country's scenic beauties and preparing films for exhibition. The earliest of these scenic films were screened at the British Empire Exhibition at Wembley, London, in 1924–25, but later films were made for weekly theatrical release throughout New Zealand and Australia. One of the most notable films made by Morton during the period of silent-film making was the two-reel Fighting fins, a record of the visit to New Zealand by American novelist Zane Grey on a deep-sea fishing expedition in 1926.
Morton's early working conditions were primitive, but they improved when the government photographic laboratory moved from its 'old tin shed' behind Parliament to premises on Lambton Quay. There, Morton and his colleagues were better equipped to meet their one-film-per-week schedule. In 1927 the contractor for the processing and printing of the Publicity Office's films, A. A. P. Mackenzie, formed Filmcraft Limited and built the Miramar film studio and laboratory, to which Morton moved in 1928.
More than 200 films had been produced by the Publicity Office before it stopped making silent films in 1930, the year after 'talkies' arrived in New Zealand. Filmcraft invested in sound equipment, but administrative changes and staff cuts by its principal client, the Publicity Office, led to a drastic reduction in demand for its facilities. As Morton later recalled, the company's staff 'went from forty to four overnight, and the place was like a morgue'.
Over the next six years Morton, as government film supervisor, was more of a caretaker of the government's film equipment than a working film-maker, although he still managed to produce a number of shorts. In 1928 he shot the silent film Amokura in Rotorua. It was not used at the time, but when sound equipment arrived Morton wrote a script which was narrated over the film. Issued in 1934, it was screened successfully for a number of years. On 1 March 1933, at Hamilton, he married Ngaire Eleanor Andrews, a shorthand typist; they were to have one son.
In 1936 Filmcraft leased the Miramar studios to the Department of Tourist and Health Resorts and Publicity, and regular production of tourist promotion films began again. The department bought the studios outright in 1938, the year that production began on the centennial film One hundred crowded years, which Morton supervised and edited. Work was disrupted by the outbreak of the Second World War, but on its completion in 1940 the film was screened throughout New Zealand to raise funds for patriotic purposes.
Cyril Morton played a key role in setting up the New Zealand National Film Unit in 1941. He produced a series of anti-waste films to demonstrate that government film studios could play a useful role in the war effort, and worked with the journalist and film critic E. S. Andrews, who had also advocated the use of film for wartime publicity purposes. Andrews was appointed producer of the National Film Unit in August 1941, and with Morton as supervisor of production the making of war-effort films began on a regular basis.
From a small beginning the National Film Unit's 'Weekly Review' newsreel grew to become a feature of picture theatre programmes during the war, and 459 were produced between 1941 and 1950. Morton had an encyclopaedic knowledge of the unit's film stock, and often worked extremely long hours. When Andrews resigned in 1950, Morton was appointed producer of the unit with Geoffrey Scott as manager.
Two of the unit's biggest undertakings were the production of a feature-length film of the 1950 British Empire Games in Auckland, and the filming of the 1953–54 royal visit for the Eastmancolor feature Royal New Zealand journey. Morton visited England to edit the latter film with the J. Arthur Rank Organisation, the unit's co-producer. In the 1950s departmental information films, scenic films and the 'Pictorial Parade' magazine series were the unit's staple output. From the early 1960s films for television release became a new feature of its work.
Cyril Morton retired on 27 June 1963, ending 40 years in government film-making. He settled in Foxton, where he pursued his hobbies of railway modelling and painting. He died in Levin on 25 June 1986, survived by his son; Ngaire had died five years earlier.