The move aims to support the growth of Guinness Draught and Guinness Zero.
The company will invest £24.5 million (€29.4 million) at its facility in Belfast in doubling in canning capacity.
It will convert existing warehouses into a new state-of-the-art packaging line capable of producing 72,000 cans per hour.
Diageo will invest £16 million (€19.2 million) at the Runcorn site to upgrade its bottling line and expand its warehousing capacity.
'A Significant Investment'
Commenting on the investment, Aidan Crowe, operations director for beer at Diageo, stated, “This expansion is a significant investment in the development of our packaging facilities.
“The projects in Belfast and Runcorn will support our growth ambitions, helping us to deliver end-to-end product innovation, and reinforce our agility to meet demand and provide excellent service to our customers around the world.”
The Guinness maker hopes to enhance efficiency and competitiveness at both sites through this investment.
Diageo reported a 16% increase in first-half sales in January, as more consumers bought high-end spirits and bars increased orders as they reopened after coronavirus lockdowns. It benefited from shoppers stocking up on spirits and beers at home during the COVID-19 pandemic, often trading up to more expensive types of alcohol.