Donald Glenoe McIntyre, auditor and amateur astronomer, was the only child of Donald Arderne McIntyre, postmaster at George, and his wife Florence Maud, born Philipson-Stow. He attended the Boys' High School, George, and passed the matriculation examination of the University of the Cape of Good Hope in 1907. The next two years he spent at the Diocesan College, Cape Town, studying surveying. He did not complete the course, but retained a life-long interest in the college. After leaving the college he studied accountancy. During World War I (1914-1918) he served with the South African Forces in East Africa. Upon his return he settled in Cape Town in the employ of E.R. Syfret and Co. as an auditor, a post he held to the mid-nineteen-forties.
McIntyre became a member of the British Astronomical Society in 1912 and was later elected a Fellow of the Royal Astronomical Society (FRAS). He joined the Cape Astronomical Association in 1916, and remained a member (later an honorary member) of its successor, the Astronomical Society of South Africa (ASSA), until his death. In 1921 he was joint vice-president of the Cape Astronomical Association and in 1924-1925 served as chairman of the Cape Centre of ASSA. He was a member of the society's council until 1934, serving as president for 1933/4. He was one of the society's representatives on the South African National Committee on Astronomy in 1929. In 1922 ASSA formed a Meteor Section with him as director. He and W. Reid* at first obtained useful results, but the section failed after a few years owing to a lack of observers. During his early years in the Cape Association he regularly delivered one or more lectures each year and by means of articles in the Cape Times, radio talks and public lectures, kept the public informed on developments in astronomy.
On 14 March 1920 McIntyre, C.L. O'B Dutton and W. Reid*, at the latter's observatory in Rondebosch, first observed that the rings of Saturn are transparent. McIntyre later published a paper on "The transparency of Saturn's rings" in the Journal of the Astronomical Society of South Africa (1935, Vol. 3, p. 139). Other papers by him in the same journal dealt with "The distance, brightness and dimensions of a star" (1923) and "A fall of meteorites in the Cold Bokkeveld in 1838"(1931).
McIntyre had a strong interest also in the history of astronomy, particularly in his later years. His publications on this subject included Comets in old Cape records (1949, 15 p.), and "An astronomical bi-centenary: The Abbe de Lacaille's visit to the Cape, 1751-1753" (Quarterly Bulletin of the South African Library, 1951). At some time he presented a 250 mm reflecting telescope to the Diocesan College Astronomical Society.
In addition to his profession and astronomy McIntyre was an authority on chess problems. On this topic he wrote Some problems for my friends (1957) and Sonatas in chess (1960), while his collection of books on chess is in the National Library of South Africa, Cape Town. As an authority on organs he was elected an honorary member of the Cape Guild of Organists and wrote Early organs and organists at the Cape (1934) and Chapels and organs at the Diocesan College (1934). He also wrote The Diocesan College, Rondebosch, South Africa: A century of 'Bishops' (1950) to mark the centenary of the foundation of his old school. He was not married.