Buchanan was born in Dumbarton on 10 April 1972 and brought up on the Isle of Mull. As a child, Buchanan was a fan of David Attenborough's television programmes and Survival, a nature programme.
Buchanan's career in wildlife photography has yielded a number of critically acclaimed documentaries, shot variously in Asia (especially the Indian Subcontinent), Latin America, Europe and Africa. His career began when Nick Gordon, whose wife owned the restaurant Buchanan was working in, invited Buchanan to become Gordon's camera assistant for a project he was completing in Sierra Leone. Buchanan was there for almost a year before the project had to be abandoned due to the danger presented by the civil unrest in the country. Buchanan left school to join Nick Gordon on this trip and continued to work with him on his next projects in Venezuela and Brazil.
Buchanan began to work independently in 1995 and in time became known for his films of big cats and worked on Big Cat Diary. He also returned to his home on the Isle of Mull to film white tailed eagles. The resulting 2005 Natural World episode, "Eagle Island", received good reviews. (It was broadcast on 3 May 2009 as "Eagles of Mull" on Nature.) He also filmed the Natural World episode "Leopards of Yala".
Buchanan has filmed foxes for Springwatch and Autumnwatch in Glasgow, where he currently lives. Buchanan's coverage of grey seal pups was identified as one of the highlights of the programme. He then returned for Springwatch 2008 completing a series on people with amazing wildlife stories including a one-off Springwatch special. In Autumnwatch 2008 he travelled to the Farne Islands to film grey seal pups again. In early 2009 Buchanan worked with the BBC, filming the Lost Land of the Volcano.Filming took place during the month of February 2009, around Papua New Guinea, and its islands. In December 2010, a documentary called The Bear Family and Me aired on the BBC. It showed the year which Buchanan spent with black bears in the U.S. state of Minnesota. In January 2013, Buchanan presented and partially filmed The Polar Bear Family and Me for the BBC, covering the life of a mother polar bear and her cubs in the spring, summer and autumn.
In 2015, he presented the acclaimed documentary Leopard in the City on the leopards of Sanjay Gandhi National Park in the Borivli section of northern Mumbai in India, on the "urban leopards" of the area, which prey almost entirely on stray dogs. 
In December 2014, another '...& Me' 2-part series was broadcast on BBC Two. For this series, The Snow Wolf Family & Me, Buchanan visited Ellesmere Island in Canada in both summer and autumn. This was shortly followed, in February 2015, by Super Cute Animals, a 60-minute documentary.
Buchanan frequently mentions missing his family at various points within his shows. "The Bear Family & Me" includes a segment in which his wife (Wendy) and their two children (Lola and Harris) visit him.
- "Gordon Buchanan Cameraman". Mike Birkhead Associates. Retrieved 2008-06-21.
- McQullian, Rebecca (2007-08-25). "From stones in a can to new depths of learning". The Herald. Retrieved 2008-06-21.
- "Leopards of Yala Interview". PBS. Retrieved 2008-06-21.
- Stoker, Leah. "In Profile: Gordon Buchanan". Broadcast Freelancer. Retrieved 2008-06-21.
- Gordon Buchanan IMDB profile
- Wollaston, Sam (2005-10-27). "Last night's TV". The Guardian. Retrieved 2008-06-21.
- BBC Nature Autumn Watch Videos
- McQuillan, Rebecca. "Wild nights, sex and violence … it’s a natural ratings winner". The Herald. Retrieved 2008-06-21.
- Noonan, Damian (2007-10-27). "Top 10 autumn nature links". Telegraph. Retrieved 2008-06-21.
- "BBC: Springwatch 2008". a2mediagroup. 2008-05-23. Retrieved 2008-06-21.
- "Springwatch Specials". BBC. Archived from the original on 5 February 2009. Retrieved 21 June 2008.
- "BBC: The Polar Bear Family & Me". BBC. Retrieved 2013-01-10.
- "Gordon Buchanan announced as new Patron for Trees for Life". Trees For Life. 2013-04-01. Retrieved 2013-05-02.
- "Wild cameraman at work: Gordon Buchanan picks up honour". University of Stirling. 2013-06-27. Retrieved 2013-07-12.
- The Bear Family & Me, Season 1, Episode 2, "Summer", 41 minutes into the show