Morgan, who has held the role since 2007, will retire from the executive committee on June 30 2014.
Before taking on his current role, Morgan was president of Diageo Europe for seven years.
A number of positions
He has held a number of marketing, strategy and management positions with Guinness and Diageo since joining Guinness in 1987.
Ivan Menezes, chief executive of Diageo, said Morgan had played an instrumental part in growing the business over the past 27 years.
“He has spent over 12 years on our executive committee and has enjoyed a career of enormous breadth and contribution,” Menezes added. “I am grateful to him for the major role he has played in extending Diageo's outstanding global reach and presence in high growth markets. Everyone at Diageo wishes him well in his future endeavours.”