Adamson was born 3 February 1906 in Dholpur, Rajasthan, India (then British India). He first visited Kenya in 1924. After a series of jobs, which included time as a gold prospector, goat trader, and professional safari hunter, he joined Kenya's game department in 1938 and was Senior Game Warden of the Northern Frontier District. Six years later he married Joy. It was in 1956 that he raised the lioness cub Elsa who became the subject of the 1966 feature film Born Free. In 1970, he also raised a lion called Christian the Lion. The video of the reunion of Christian and his owners gained about 5 million veiwers on Youtube.

Adamson retired as a game warden in 1961 and devoted himself to his many lions. In 1970, he moved to the Kora National Reserve in northern Kenya to continue the rehabilitation of captive or orphaned big cats for eventual reintroduction into the wild. George and Joy separated in 1970, but continued to spend Christmas holiday together until she was murdered on January 3rd, 1980.

On 20 August 1989, the 83-year-old Adamson was shot to death at Kora Reserve by Somali bandits when he went to the aid of a tourist.

He is buried at the reserve next to his lion friend named Boy. Also buried there are George's brother, Terrance Adamson and Supercub the lion.

• Born Free (1966), based on the book of the same name by Joy Adamson about Elsa the Lioness, who was rehabilitated into in the wild but remained in a friendly relationship with George and Joy Adamson. Stars Virginia McKenna as Joy Adamson and Bill Travers as George Adamson. George Adamson served as Chief Technical Advisor.
• The Lions Are Free (1967), The true story of what happened to the lions Boy, Girl, Ugas, Mara, Henrietta, Little Elsa and other lions who starred in the popular movie classic Born Free. George Adamson rehabilitated many of these lions after the movie Born Free was completed. Documentary-style film about George Adamson and his lions.
• An Elephant Called Slowly (1969) Travelogue featuring George Adamson, Bill Travers and Virginia McKenna.
• Lord of the Lions...Adamson of Africa - Filmed in the Kora Reserve in Kenya only months before George was murdered. About 53 minutes.

• Living Free (1972) Sequel to Born Free, Stars Nigel Davenport as George Adamson, and Susan Hampshire as Joy Adamson.
• Christian the Lion (1972) Documentary of Christian the lion and his journey to George Adamson; Written, produced and directed by Bill Travers and James Hill, the director of Born Free.
• Born Free (television series) (1974), loose adaptation starring Gary Collins and Diana Muldaur
• To Walk With Lions (1999) Feature film; Stars Richard Harris as George Adamson.