The appointment represents a homecoming for Gray who is from Galashiels and played for his local club and the Border Reivers as well as Scotland age grade sides.
He has been appointed “defensive contact specialist” on a consultancy basis by Cotter after garnering an impressive reputation with the South Africa national side.
He has spent the past three seasons as their specialist breakdown coach, helping the Springboks to a third-place finish at last year’s Rugby World Cup. He has also worked with the Blitzbokke sevens side.
The surprise resignation of Boks head coach Heyneke Meyer last month changed the dynamic in South Africa and allowed Scotland to make their move for Gray.
He will link up immediately with the national side who are due to convene in St Andrews today for a three-day training camp ahead of the Six Nations, which kicks off for Scotland on 6 February with a Calcutta Cup clash against England at BT Murrayfield.
“It’s a great honour to coach any country but to be offered the opportunity to coach your own is something special indeed,” Gray said yesterday.
“The defensive breakdown is an area highlighted by the coaches as an area for improvement, for which I’ve been given a very specific brief to work alongside defence coach Matt Taylor for the seven-week period of the RBS Six Nations. It’s a great honour and I’m looking forward to joining up with the squad in camp in St Andrews this Sunday.”
Gray was a Scottish Rugby employee from 1994 to 2006, when he worked as a development manager, academy manager and coach to various Scotland age-grade sides, the South of Scotland, Gala and Biggar.
He was in opposition to Scotland during the World Cup pool match at St James’ Park last October as South Africa beat the Scots 34-16.
Cotter, said: “On behalf of the national team I’d like to welcome Richie to our coaching set-up for the 2016 RBS Six Nations. We’re looking forward to adding his experience and passion to the group.”