Colin Alistair Ronan was educated at Abingdon School in Oxfordshire and served in the British Army from 1940 to 1946, achieving the rank of major. After the war, he obtained a BSc in Astronomy and took an administrative post at the secretariat of The Royal Society. There, he did an MSc in the History and Philosophy of Science under Herbert Dingle at University College London.
After leaving the Royal Society he took up writing, and during a long career, he was an author produced over forty books, mainly on astronomy, and the history and philosophy of science. Later, he collaborated with Joseph Needham on an abridgement of Needham's great work on China, producing The Shorter Science and Civilization in China in several volumes.
He played key roles in the administration of the British Astronomical Association, where he was director from 1953-1965 and president from 1989 to 1991, and for many years, he was the editor of its journal and the director of the historical section.
In 1991, Ronan delivered a Presidential Address in which he argued that Leonard Digges, father of Thomas Digges was the originator of the reflecting telescope sometime between 1540 and 1559, over a century before Isaac Newton, who is usually credited with having built the first such telescope around 1668.
For a considerable period in the 1980s and early 1990s, he collaborated with Sir Patrick Moore in lecture tours. They took the form of weekend residential symposia on single topics such as the return of Halley’s Comet. Notable and hilarious, the interplay between Ronan's sober and intellectual analysis along with Moore’s more extravagant character led frequent disagreements that were usually solved over several bottles of red wine. The weekends were an enormous success and made a valuable and irreplaceable contribution to the amateur astronomical scene.
With his second wife, Ann, he founded the Ronan Picture Library, which specialises in scientific and historical pictures. Among his many books on the history of science were studies of scientists such as Galileo, William Herschel and Edmond Halley. He also wrote scientific books for children, along with books such as The Practical Astronomer (1981), written for beginner amateur astronomers.
- Universe: The Cosmos Explained. Quantum Books. 2007.
- The Shorter Science and Civilization in China (with Joseph Needham). Cambridge University Press in 6 volumes. 1978–1995.
- Science Explained. Henry Holt. 1993.
- The Natural History of the Universe. Transworld Publishers, Macmillan. 1991.
- The Universe Explained. Henry Holt, Thames and Hudson. 1994.
- Science: Its History & Development Among the World's Cultures. Facts on File. 1985.
- The Skywatcher's Handbook: night and day, what to look for in the heavens above. Corgi, Crown. 1985.
- Amateur Astronomy-A Comprehensive & Practical Survey. Newnes Books. 1984.
- Science: its history and development among the world's cultures. Facts on File. 1983.
- The Cambridge Illustrated History of the World's Science. Cambridge University Press. 1983.
- Atlas of Scientific Discovery. Crescent Books, Apple Press. 1983.
- Deep Space. Scribner. 1982.
- The Practical Astronomer. Macmillan, (Crescent 1988, Bloomsbury 1992). 1981.
- Encyclopedia of Astronomy. Hamlyn. 1979.
- Greenwich Observatory: 300 years of astronomy. Times Books. 1975.
- Galileo. Weidenfeld & Nicolson, Putnam. 1974.
- Astronomy: Illustrated Sources in History. David and Charles, Barnes and Noble. 1973.
- Lost Discoveries: the forgotten science of the ancient world. McGraw Hill. 1973.
- Discovering the Universe: a history of astronomy. Basic Books 1971, Heinemann 1972. 1971.
- Book of Science. Oxford University Press. 1971.
- Sir Isaac Newton. International Textbook Company 1971, Shire 1976. 1971.
- Edmond Halley: Genius in Eclipse. Doubleday. 1969.
- Astronomers Royal. Doubleday. 1969.
- Their Majesties' Astronomers. Bodley Head. 1967.
- Invisible Astronomy. Eyre and Spottiswood 1967, JB Lippincott Co 1972. 1967.
- The Meaning of Sound. Hart Publishing Company. 1967.
- The Ages of Science. George G Harrup Co. 1966.
- Exploring Space. Odhams Books Limited. 1966.
- The Easy Way to Understand Photography. Max Parrish. 1966.
- The Universe. Franklin Watts, NY, later OUP. 1966.
- The Stars (Natural Science Picture Books). McGraw Hill, Bodley Head Children's Books. 1965.
- Man Probes the Universe-the Story of Astronomy. Natural History Press. 1964.
- Optical Astronomy-Changing Horizons. Phoenix House, Roy Publishers. 1964.
- The Astronomers. Evans Brothers. 1964.
- Radio and Radar Astronomy. Doubleday. 1963.
- Clocks and Watches. Doubleday. 1962.
- The Meaning of Light. Weidenfeld & Nicolson. 1962.
- Changing Views of the Universe. Eyre and Spottiswood, Macmillan. 1961.
- The Earth from Pole to Pole. George G Harrup Co. 1961.
- Moore, P. (1996). "Colin Alistair Ronan (1920–1995)". Quarterly Journal of the Royal Astronomical Society. Royal Astronomical Society. 37 (1): 93–94. Bibcode:1996QJRAS..37...93M. Retrieved 13 June 2016.
- Moore, P. (1995). "Colin Alistair Ronan (1920–1995)". Journal of the British Astronomical Association. British Astronomical Association. 105 (5): 262. Bibcode:1995JBAA..105..288M. Retrieved 13 June 2016.
- "BAA Historical Section - A Brief History". British Astronomical Association.
- Ronan, Colin A. "The origins of the reflecting telescope." Journal of the British Astronomical Association 101 (1991): 335-342
- "The Ann Ronan Picture Library". ANN RONAN PICTURE LIBRARY.
- "(4024) Ronan = 1931 GJ = 1957 WB1 = 1976 JX1 = 1981 WQ". IAU Minor Planet Center.