Hefin, who has played for the Warriors since 2005, will make his Scotland representative debut having qualified through residency.
Looking forward to playing in the blue of Scotland, Hefin said: “It was fantastic to get the call-up to the Scotland 7s squad. They made a great finish to the World Cup Sevens and it’s a real honour for me to be involved.
"Qualifying to play for Scotland has been in the back of my mind the past few years and it’ll be a great feeling to finally pull on that blue jersey.”
Scotland 7s coach Stephen Gemmell said: “Hefin has always been an exciting player with Glasgow, he has a real cutting edge, and this is a fantastic opportunity to play for Scotland in a big tournament."
Hong Kong Pool F: Kenya, USA, Scotland, West Indies
Scotland 7s’ Pool F fixtures at the IRB Hong Kong Sevens (27-29 March):
Day 1 – Scotland v USA, kick-off 7:10pm HKT, 11:10am GMT
Day 2 – Kenya v Scotland, kick-off 12:42pm HKT, 4:42am GMT
Day 2 – Scotland v West Indies, kick-off 2:54pm HKT, 6:54am GMT
Adelaide Pool B: Argentina, Fiji, France, Scotland
Scotland 7s’ Pool B fixtures at the IRB Adelaide Sevens (3-5 April):
Day 1 – Fiji v Scotland, kick-off 6:58pm CST, 7:58am GMT
Day 2 – Argentina v Scotland, kick-off 1:43pm CST, 2:43am GMT
Day 2 – France v Scotland, kick-off 4:10pm CST, 5:10am GMT
Scotland 7s squad (sponsor Murray) to compete at the IRB Sevens World Series events in Hong Kong (27-29 March) and Adelaide (3-5 April): Scott Forrest (Ayr)* CAPTAIN, Mike Adamson (Glasgow Warriors), Andrew Easson (Edinburgh), Roddy Grant (West Of Scotland)*, Graham Hogg (Hawick)*, Jamie Hunter (West Of Scotland)*, Rory Hutton (Hawick)*, Chris Kinloch (Glasgow Warriors), Calum MacRae (Edinburgh), Hefin O'Hare (Glasgow Warriors), Scott Riddell (Blaydon), Jim Thompson (Edinburgh)
* = Member of Scottish Rugby’s Contracted National Academy