One by One is a British television series made by the BBC between 29 January 1984 and 2 May 1987.

The series, created by Anthony Read, was based on the early life and writings of international veterinary surgeon David Taylor. Called Donald Turner in the series, the show follows his work caring for exotic animals at zoos in Britain, from the 1950s to the 1970s. Each series was set during a different decade, with exteriors filmed at Dudley Zoo, Chester Zoo and Knowsley Safari Park.

Thirty-two episodes were made over three series, transmitted on BBC1 in the early parts of 1984, 1985 & 1987. BBC1 repeated series 2 during the early months of 1986, as no new series had been made that year. The third series was also repeated on BBC1 over the Spring & Summer of 1988.