Barry O’Sullivan – Managing Director, Diageo Great Britain
Barry O’Sullivan is Managing Director of Diageo Great Britain, starting his role on 1st July 2025.
He oversees Diageo Great Britain’s business from the company’s global headquarters in London, guiding teams from all corners of the business including innovation, supply, sales, marketing, and legal. Diageo GB is Diageo’s home market and second largest globally, accounting for 10% of all UK food and drink exports. With 530 employees, Diageo GB is proud to be the country’s #1 supplier within the on-trade, off-trade, and across the individual vodka, gin, rum and non-alc spirits categories.
Prior to joining GB, Barry spent four years as Managing Director of Diageo Ireland, delivering consistent, sustainable growth in the Island of Ireland market. Under Barry’s leadership, the market made groundbreaking investments in Guinness, with €100 million dedicated to decarbonising Dublin’s St. James’s Gate and a €30 million investment in the production of Guinness 0.0. He likewise navigated the market through the challenges of the COVID-19 pandemic and adapted to shifts in consumer behaviour and economic pressures
Before joining Diageo, O’Sullivan was at Mars, where he held senior positions across Australia, Mexico, and the Middle East. Notably, he served as General Manager of Mars Petcare in Australia and New Zealand, as well as leading Mars Chocolate in Mexico. During his time with Mars, O’Sullivan and his family lived in several countries, moving abroad in 2010.
O’Sullivan grew up in Baldoyle, north Dublin, and both of his parents are from Waterford. His father was a sales and marketing director, while his mother worked as a company secretary before focusing on raising their four sons. He attended secondary school at Belvedere College before completing an Arts degree at UCD followed by a master’s at the Smurfit Business School, Dublin.
O’Sullivan’s family home is in Sutton, Dublin, where he commutes from London to spend weekends with his wife, Priya Rana, and their two daughters, Kiara and Karina. The family also has a rescue dog named Lola, whom they adopted while living in Australia and brought back to live in Ireland with them.