Bradley Carnegie Thorn is a New Zealand former rugby league and rugby union footballer. 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 attained the highest level of international recognition as a dual-code competitor, excelling in two of the most challenging sporting disciplines down under. Sustaining elite-level competition for such an extended duration is a remarkable achievement, unlikely to be replicated.

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 (1984), and 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.

Thorn played rugby league for the Brisbane Broncos in the Australian National Rugby League (NRL) competition for a total of ten seasons in two spells and represented Queensland in the State of Origin series. He played eight times for Australia – five for the Kangaroos, and three games for the Super League Australia team. His preferred position in rugby league was in the second-row, though he was equally effective as a prop.

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-Bankstown Bulldogs. At season's end he was awarded 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.

In the 1997 Super League season, Thorn played in all three games for Queensland in that year's Super League Tri-series. He also made his international debut for Australia against New Zealand. Thorn won his first premiership with the Broncos when they defeated the Cronulla-Sutherland Sharks in the 1997 Super League grand final in Brisbane. Following the sport's re-unification under the National Rugby League, Thorn was selected in Game II of the 1998 State of Origin series. He also continued to represent Australia in all three Tests of the 1998 international series against New Zealand. Thorn also played at second-row forward in the Broncos' victory at the 1998 NRL Grand Final, winning his second premiership ring.

Thorn was selected to play for Queensland again in Game III of 1999 State of Origin series and all three matches of the 2000 State of Origin series. He then played at second-row forward for the Broncos in their 2000 NRL Grand Final win over the Sydney Roosters, claiming a third premiership. In 2005 Thorn moved back to Brisbane and the National Rugby League, again playing with the Broncos for another three years. He enjoyed further representative selection for Queensland in all three games of the 2005 State of Origin series, scoring a try in Game II. Thorn claimed another premiership ring when he played at second-row in the Broncos' 2006 NRL Grand Final victory over the Melbourne Storm.

During the 2007 NRL season at the Broncos' 20-year anniversary celebration, the club announced a list of the 20 best players to play for them to date which included Thorn. At the close of the 2007 NRL season Thorn switched codes once again, moving back to New Zealand to continue his rugby union career. In 2001 Thorn moved to New Zealand and switched to rugby union, playing for the Crusaders in the Super 12 and Canterbury in the National Provincial Championship. He was part of the Canterbury squad that won the NPC in 2001. Thorn went on to play for New Zealand's All Blacks, appearing in 12 tests, including the 2003 Rugby Union World Cup. He thus became a dual rugby-code international, the second man in history (after Bill Hardcastle) to have represented Australia in league and New Zealand in union. In 2004 Thorn won the NPC with Canterbury. He also won the Tri-Nations with NZ in 2003.

He won a second Tri-Nations with New Zealand in 2008 and a third in 2010. On 23 October 2011, Thorn was part of the All Blacks team which won the Rugby World Cup 2011, beating France 8–7 in the Final at Eden Park in Auckland. In October 2012, it was reported that Thorn has agreed in principle to join the Highlanders Super rugby franchise for the 2013 season. Thorn helped Ireland's Leinster lift the 2012 Heineken Cup, becoming the first man to play in victorious World Cup, Super Rugby and European Cup teams. In April 2015, Thorn announced that he would retire at the end of the 2014/15 season. In 2016, Thorn came out of retirement, aged 41, and played for Queensland Country in Australia's National Rugby Championship.

Thorn's extended playing career - 22 seasons as an elite professional has been attributed to his professional approach, including focuses on stretching, listening to his body, and doing only light weights when he felt that was right for him. In April 2023, Thorn confirmed he will finish as coach of the Queensland Reds at the conclusion of the 2023 Super Rugby Pacific season. Thorn is now an assistant head coach of the Brisbane Boys' College 1st XV.