Dougall was born and educated in Croydon, Surrey. He attended Whitgift School but did not carry on to university despite having some talent in languages, specifically French and German. He joined the BBC initially in the accounts department, but soon found a job as an announcer for the BBC Empire Service on his 21st birthday in 1934. By 1939, he had risen to the position of senior announcer and his was the voice that announced to the world Britain's declaration of war on Germany in September of that year. Shortly before this announcement, he had transmitted a message as an "anonymous" Englishman, imploring Germany to withdraw its forces and avert the impending conflict: Dougall worked as a radio reporter during the early part of the Second World War, but also served with the Royal Navy from 1942. He resumed his broadcasting career after demobilisation in 1946 as an announcer and newsreader for the BBC Home Service. In 1947, Dougall was appointed Programme Manager for the BBC's Far Eastern Service, a position which required him to move to Singapore.
Television news
Dougall's radio work took a back seat when he returned to London in 1951 to work as a television newsreader. Between 1946 and 1955, the BBC News was merely voiced over a photograph of Big Ben, a measure sanctioned by Chief News Editor Tahu Hole to reinforce the absolute impartiality for which the Corporation was renowned. However, the coming of commercial television and ITN in 1955 prompted the BBC to have its newsreaders perform to camera - indeed, they began this approach only three weeks before ITN began transmission. Dougall was among the first of these newsreaders to appear in-vision in 1955. Dougall presented general BBC News reports and the Newsroom programme during the 1960s and was appointed a Member of the Most Excellent Order of the British Empire in 1965, receiving his honour on the same day as the Beatles. He was the first person to present the long-running BBC Nine O'Clock News in 1970, continuing in this role until his retirement from the newsroom in 1973.
Post-retirement
Like Peter Woods, Richard Baker and Kenneth Kendall, Dougall was considered an archetypal newsreader and frequently appeared as himself in comedy programmes of the 1970s and early 1980s, including The Goodies and Yes Minister. He also presented seven series of Channel 4's over-60s programme Years Ahead over four years and appeared in an advertising campaign for the jewellers Prestons of Bolton during the 1980s. His voice provides the news announcement that Big Ben chimed seven times at 6 p.m. in the Bond film Thunderball. Dougall was also known for his love of animals and birds and he was president of the RSPB for a five-year period. He wrote several books about birds in the 1970s and an autobiography, In and Out of the Box, a witty account of life in the Reithian BBC, which he had joined as its youngest staff announcer on his 21st birthday in 1934, and beyond. He lived in Walberswick in Suffolk though his main home for many years was in Hampstead in London.