Bradley Carnegie Thorn (born 3 February 1975) is an Australian and New Zealand rugby union coach and former rugby league and rugby union player. Born in New Zealand, he represented Australia in rugby league and New Zealand in rugby union in a twenty-two year career as a player, starting at age nineteen and finishing at age forty-one. He was the head coach of the Queensland Reds in Super Rugby Pacific.

Thorn played rugby league for the Brisbane Broncos in the National Rugby League (NRL) and Super League for ten seasons across two spells, winning four grand finals, and represented Queensland in the State of Origin series. He played eight times for Australia – five for the Kangaroos, and three for the Super League Australia team. His usual position in rugby league was in the second-row, and he sometimes played as a prop. In 2000 Thorn was awarded the Australian Sports Medal for his contribution to Australia's international standing in rugby league.

He first moved to rugby union in 2001, in his mid-twenties, and played as a lock. Over two spells in the sport, he became the first player to win a World Cup, a Super Rugby title and the Heineken Cup. He won 59 international caps for New Zealand, and was part of the team that won the 2011 Rugby World Cup. Thorn is the oldest player to play in the final of a World Cup and win it, aged 36 years, 262 days.

Thorn was born in Mosgiel, just outside Dunedin in south-eastern Otago. When Thorn was five years old, his family moved to south-central Otago (Cromwell/Bannockburn). Moving again, Thorn’s family left for Brisbane, Queensland, Australia when he was nine years old, and he was educated at Aspley East State School and Aspley State High School.

Growing up in the northern suburbs of Brisbane, Thorn played junior rugby league for Norths Aspley and Wests Arana Panthers. By the age of 12, Thorn had stopped playing rugby league in favour of pursuing a career in Australian rules football (AFL) and was showing promising signs when he was selected to represent the Queensland under-12 state team before a chance meeting with Wayne Bennett at 13 years of age convinced him to return to rugby league.

With the help of Kangaroos teammate Jason Stevens, Thorn became a born-again Christian in 1998. Thorn stated to The Times: “I do feel now I have purpose, believe there is a God that loves me. I want be a good father and husband and in a footy context give my best.” In 2011, Thorn said “I had money, a car, a house – I thought these things would make me happy. But once I got there and got all these things, I still felt unfulfilled. I felt empty ... it was only when I put my faith in Jesus that life changed for me.”

Thorn made his first grade debut in the NSWRL for the Brisbane Broncos, who were then defending premiers, in the 1994 Winfield Cup season's 12th round against the Canterbury Bulldogs. At season's end he won the club's rookie of the year award.

At the outbreak of the Super League war in 1995 Thorn, along with the rest of his Broncos teammates and players of several other clubs, was aligned with Super League and so ineligible for selection in the Australian Rugby League's 1995 State of Origin series or post-season 1995 Rugby League World Cup. The following year, when all players were again allowed to be selected for representative football, Thorn's debut for the Queensland Maroons came in Game I of the 1996 State of Origin series. He held his place at second-row forward for all three games of that series.