Gary Henley-Smith is a New Zealand sprinter and professional rugby league footballer who played in the 1970s and 1980s. He played club-level rugby league (RL) for Wigan (Heritage № 821) and Fulham RLFC (Heritage № 85) as a wing, i.e. number 2 or 5.
Henley-Smith attended Auckland Grammar School, where he was Auckland and New Zealand secondary schools senior boys 100m and 200m champion and held several records.
He held the New Zealand junior men's 100m and 200m records at 10.4s and 21.7s. His 10.4s 100m record, set in 1977, stood for 13 years.
Henley-Smith was a member of the Oceania team at the World Cup in Germany in 1977. That same year he joined Washington State University on a scholarship, spending four years in the United States. When he returned he was a member of Waitakere City Athletic Club and was the New Zealand Amateur Athletic Association 100m and 200m national champion in 1982 and 1983.
He missed selection for the Commonwealth Games in 1978 due to a stress fracture.
He competed in New Zealand's 4 × 100 metres relay team at the 1990 Commonwealth Games in Auckland.
Henley-Smith spent the 1985–86 Rugby Football League season playing rugby league in England, joining Wigan, he played right wing, i.e. number 2, in Wigan's 14–8 victory over New Zealand in the 1985 New Zealand rugby league tour of Great Britain and France match at Central Park, Wigan on Sunday 6 October 1985, and played right wing (replaced by interchange/substitute Steve Hampson) in Wigan's 34–8 victory over Warrington in the 1985 Lancashire County Cup Final during the 1985–86 season at Knowsley Road, St. Helens, on Sunday 13 October 1985.
Henley-Smith spent a number of years as a physical education teacher at St Paul's Collegiate School in Hamilton, New Zealand, before moving to Scots College, Wellington as Director of Boarding.