Kelly David Robert Brown scored his fourth try for Scotland when he touched down in the second-half of the opening 2011 RBS 6 Nations Championship match against France in Paris and was arguably Scotland's most consistent forward of the tournament.

Kelly had a try-scoring debut for Scotland in the 39-19 win over Romania in Bucharest in June 2005. His second Scotland try followed in the 34-22 victory against the Pacific Islanders at Murrayfield in the Bank of Scotland Corporate international in November 2006. His first start in a Six Nations match (his ninth Test) followed against England at Twickenham on the opening day of the 2007 championship, and he marked his World Cup debut with a try as a replacement in the 56-10 win against Portugal later that year in St Etienne. A fortnight before the Bucharest international in 2005 he made his senior Scotland debut in the non-cap international game against the Barbarians at Pittodrie, Aberdeen, his solid performance contributing to the 38-7 win, the first time Scotland had beaten the invitation club.

Kelly scored a try on his Scotland A debut in the 69-3 win against Georgia at Firhill, Glasgow, in November 2008, though by then he already had 26 full caps to his name. Seven months later he played in all three matches for the Scotland A team who won the IRB Nations Cup in Bucharest, and later that year he was in the Scotland A team who beat Tonga 38-7 at Netherdale, Galashiels.

A former pupil of Earlston High School, Kelly studied sports science at Edinburgh University before taking up rugby as a career. He has represented Scotland at four age levels (under-21, under-19, under-18, and under-16) as well as in the sevens squad. His under-19 honours included playing all four games in the 2001 world championship in Santiago, Chile. He went on to play 15 times for Scotland under-21, finishing with a victory against England at Newbury in the age group’s 2003 world championship. Kelly, who joined Glasgow Warriors from Border Reivers in summer 2007, has represented The Borders at under-15, under-16, under-18, under-19, and under-20. He has also had considerable experience in the Scotland seven-a-side squad, playing in the IRB Rugby World Cup tournament in Hong Kong in 2005. There he scored two tries in helping Scotland to a top-eight finish in the tournament.

His elder brother, Rowan, represented Scottish Schools.