Dame Tanni Grey-Thompson (b. July 26, 1969, Cardiff) is a British wheelchair athlete, and considered to be the most successful in the country. Affected with spina bifida from birth, Thompson competes in wheelchair events over a wide range of distances, first competing in the 100 m at the Junior National Games for Wales in 1984. Over her career to date, she has won a total of 14 Paralympic medals, including 11 golds, held over 30 world records, and won the London Marathon six times between 1997 and 2002.

In 2000 she was awarded the Helen Rollason Award for her performance at the 2000 Summer Paralympics, and was given the OBE for services to sport. In 2001, she was given an honorary degree by Loughborough University, awarded Doctor of Technology, having previously graduated from the university ten years earlier, with an honours degree in Politics and Social Administration. In the 2005 New Year's Honours List, her continuing services to Disabled Sport were rewarded with the honour of Dame Commander of the Order of the British Empire.

Tanni is married, with one daughter, Cerys.