Bibby was born in the Wirral, Cheshire, the son of a North Wales farmer. He was educated at Oundle School, Northamptonshire, and at St John's College, Cambridge, graduating in natural sciences. He gained his PhD for a classic study on the ecology and conservation of Dartford warblers.
Bibby was a research staff member for the Royal Society for the Protection of Birds from 1971 to 1986, and the head of Conservation Science from 1986 to 1991. In 1991, he moved to BirdLife International, where he led their research team and a major research program, with projects in over 70 countries. In 2001 he became a self-employed environmental consultant. He was also a member of the Rare Breeding Birds Panel, and the founding editor of the British Trust for Ornithology journal Ringing and Migration.
His major contributions were in the development of quantitative approaches to the study of birds for research leading to conservation. He was also a frequent contributor to British Birds magazine.
In 1994, he was awarded the Dr A.H. Heineken Prize for Environmental Sciences for his work with BirdLife International, and in June 2004, he received the RSPB Medal in recognition of his contribution to ornithology.
He learned that he had an incurable cancer in March 2004 and, on 7 August 2004 at the age of 55, died in his sleep. He was survived by his wife, Ruth, and three sons.
A special supplement published with Bird Conservation International (Vol 18 No 3, September 2008) was dedicated to Bibby. In it, Mike Rands, BirdLife's Chief Executive, wrote:
Colin Bibby was a truly remarkable man. He had a life-long interest in almost all things biological, and applied scientific thinking and rigour to a vast array of situations, be they the study of a particular conservation problem, or matters concerning the management of an organisation. [He] leaves a great legacy of knowledge and ideas, and this publication pays tribute to his innovative approach to the application of ornithology to conservation.
In 2017 a stained-glass painting of a Dartford Warbler, in the style of Bibby's favourite artist, Eric Ennion, was added to a window at St Michael and All Angels Church, Caldecote, Cambridgeshire in Bibby's honour. Bibby had spent the months after his fatal diagnosis fundraising for the church windows' restoration. A service of dedication for the memorial painting, on 16 July 2017, led by the Archdeacon of Cambridge, Alex Hughes, was attended by over 100 people.
- Unwin, Brian. (26 August 2004). Colin Bibby. Defending birds round the world. The Guardian.
- Marren, Peter. (16 August 2004). Colin Bibby. Ornithologist and authority on bird censusing techniques. Independent.
- Bircham, Peter (April 2013). "The amateur British ornithologist - Amber Listed?". British Birds. 106 (4): 237–238. ISSN 0007-0335.
- Green, Rhys (September 2017). "Colin's window". British Birds. 110 (9): 501.
- Anon (29 September 2008). "Bird Conservation International celebrates Colin Bibby". BirdLife International. Retrieved 23 August 2009.
- "Special Choral Evensong 6pm Sunday 16th July – Caldecote Church". Caldecote Church. Retrieved 2 September 2017.