Waddy is a surname. Notable people with the surname include:
Billy Waddy (born 1954), former professional American football player
John Waddy (disambiguation)
John Lloyd Waddy (1916–1987), senior officer and aviator in the Royal Australian Air Force (RAAF)
Jude Waddy (born 1975), former professional American football player
Ray Waddy (born 1956), former American football player
Samuel Danks Waddy (1830–1902), English politician