The agency has been instrumental in developing the brand’s global Famous For A Reason campaign.
It will now be able to lead the roll-out and development of that campaign in The Famous Grouse’s key international markets.
The whisky is exported to some 100 countries worldwide.
Alison Tuck, global marketing manager for The Famous Grouse, said: “Leith showed a clear understanding and passion for the brand. We’re delighted to be working with them on a retained basis at such an important time for The Famous Grouse.”
Richard Marsham, group managing partner at The Leith Agency, said: “The Famous Grouse is one of those global brands that we’ve always dreamed about working on.
“To win not only the ATL account, but also the BTL and digital account is a testimony to the way we think as an agency.
“We’re really excited at the prospect of working with Alison and her team and helping to move The Famous Grouse to the next level.”
Other partner agencies, including Multiply and The Big Partnership, will continue to work with Edrington on a range of BTL initiatives.
Leith represent a wide range of clients including A G Barr, Tennent’s and Drinkaware. The Famous Grouse is distilled at Perthshire’s Glenturret distillery.
Whisky production at the site can be dated back to 1775, making it the oldest working distillery in Scotland.
The Famous Grouse has been the best selling whisky in Scotland for over thirty years.
It is also the best selling whisky in the UK and the fourth most popular blended whisky in the world.
The Famous Grouse Experience, based at Glenturret, is the most popular distillery tour in Scotland.