Claude “Butch” Harmon Jr. was born on 28 August 1943 in New Rochelle, New York, to Claude Harmon Sr. — the 1948 Masters champion and longtime head pro at Winged Foot Golf Club — and Alice Harmon. He grew up alongside three younger brothers, Craig, Bill and Dick, all of whom also became golf professionals; Butch graduated from New Rochelle High School in 1962.

He turned professional in 1965, playing on the PGA Tour briefly (1970–71) and winning the 1971 Broome County Open, before serving as personal golf instructor to Morocco’s King Hassan II. He went on to become arguably golf’s most influential coach, working with Tiger Woods (1996–2002), Greg Norman, Phil Mickelson, Dustin Johnson and Rickie Fowler among others.

He began commentating for Sky Sports Golf at the 1997 Ryder Cup, becoming a fixture of its major championship coverage for over 20 years. In 2019 he stepped back from touring and full-time commentary to spend more time at home in Las Vegas, though he has continued to appear as a Sky Sports Golf analyst and podcast guest, alongside other veterans such as Ewen Murray, including as recently as the 2026 Masters preview.

He is married to Christy Harmon and has children from his marriages; his son Claude Harmon III has followed him into golf instruction.