Williams spent eight years at Asda in various roles before leaving the business in February.
He will start at Morrisons in early 2017 after a year on the sidelines and said he is “really looking forward” to the challenge as the company “continues its turnaround”.
That refers to Morrisons’ chief executive David Potts’ efforts to improve the retailer’s fortunes after profits and sales fell in the past year.
While at Asda, Williams served as category director for BWS before becoming chief merchandising officer and then chief customer officer.
Williams, who has also worked for Kwik Save, the Co-op and Musgrave, will be in charge of core grocery, BWS, baby goods, household and health and beauty offers.
When asked how it would impact on the makeup of the current BWS team, a spokesman told OLN it is too early to say what sort of shape the team will take in 2017.
Williams said it is “an exciting time to join Morrisons because it has an offer that stands out in the market and a very clear direction”.
The Morrisons wine team has won Supermarket of the Year for two years running at the International Wine Challenge.
Darren Blackhurst, Morrisons group commercial director, said: “Barry brings a wealth of trading experience and relationships with food suppliers as well as a strong understanding of our customers. His arrival is another step in shaping a Morrisons team that will listen to and work hard for customers.”