Halfway through his high school career he moved out of the Western Cape to the Midlands of Natal to attend Hilton College.
Rugby runs in Roddy's family: his grandfather (Bob) and great-uncle (George) were international referees, the latter was also Scotland full back in 1950 and 1951 and manager of the 1977 Lions in New Zealand, and Grant's father played for British Universities.
He joined Border Reivers in summer 2006 as an apprentice, and the following January he made his debut for the professional team as a substitute in the Magners League match against Newport Gwent Dragons at Rodney Parade.
In November 2008 he was the Scottish Thistles’ joint-top scorer with 45 points (nine tries) in the Singapore international sevens, and he went on to play in the Scotland squad in the 2008–09 IRB tournaments in Wellington (New Zealand), San Diego (USA), Hong Kong, Adelaide, Twickenham and Murrayfield as well as the RWC Sevens in Dubai, where he scored four tries in helping Scotland to win the Plate competition.
That same month he signed a professional contract with Edinburgh, and his Scotland A career continued with a replacement appearance in the 38–7 win against Tonga at Netherdale, Galashiels, in November 2009.
[3] On 26 December 2013, Grant made his 100th appearance for Edinburgh, leading the team out onto the Murrayfield pitch for the Boxing Day Pro12 derby clash with Glasgow Warriors.