This is a list of all the series of Countdown and their champions. This list also includes winners of Championship of Champions tournaments and the winner of Series 33, the "Supreme Championship" and the 30th Birthday Championship.
There was only one full series in 2005 because of Richard Whiteley's death — his final series, Series 53, was recorded before he was hospitalised with pneumonia. Series 54 began four months later on 31 October 2005 and, having started very late in the year, was extended to last until summer 2006. Series champions from this series onwards are awarded the Richard Whiteley Memorial Trophy along with the usual prize of the Oxford English Dictionary.
- Countdown: Spreading The Word (Granada Media, 2001) pp. 219-20, 225
- The Countdown Page Hall of Fame