Canadian-born Gwilt is a former financial journalist best known for her award-winning Miss Whisky website.
Launched in 2011, Miss Whisky has made Gwilt one of the best-known commentators in the industry.
The site was named a top ‘Website to Watch’ in the Malt Whisky Yearbook 2015, and Gwilt herself was awarded the International Whisky Ambassador of the Year title at the 2013 Spirit of Speyside Whisky Festival.
William Grant’s Ancient Reserve’s portfolio includes Girvan, Kininvie and the Rare Cask Reserves, as well as its forthcoming Ailsa Bay release, due later this month.
Gwilt’s appointment is part of the company’s wider strategic push on premium and rare whisky expressions in the UK market.
Gwilt said: “I am delighted to be taking on this role within a company that has such a strong portfolio of rare and unique whiskies.
“I am looking forward to working with like-minded people who share the same respect for whisky as I do and my ambition is to encourage more people to gain an appreciation for this fine spirit.”
Gwilt plans to maintain her Miss Whisky site, and to write about the whisky industry and the women within it, but will now be doing so in her spare time.
Jonathan Cornthwaite, senior brand manager for the William Grant & Sons UK Esoteric Whisky portfolio, added: “It is with great pleasure that we welcome Alwynne, with her wealth of unique experience.
“Alwynne is a great addition to the team and will help drive forward the William Grant & Sons UK Ancient Reserves portfolio.”
Gwilt’s role will see her be working alongside William Grant’s global whisky specialist, Kevin Abrook.