Watts, who joined Microsoft five years ago from Yahoo Southeast Asia, where he was sales director, will begin his new job on 25 January.
He will later take on the role of chief executive, replacing current president and CEO Paul Srivorakul, who is expected to shift to another position within the company.
He will later take on the role of chief executive, replacing current president and CEO Paul Srivorakul, who is expected to shift to another position within the company.
"Leaving Microsoft is the hardest professional decision I've ever had to make," said Watts. "When I started, we were just four people. Now we have unrivalled revenue growth in this region, and I leave with the business is in great shape."
Microsoft has yet to decide on a successor for Watts, but is believed to be looking outside the company as well as internally to replace him.
Watts' career spans 17 years to date, starting in outdoor media before entering the digital marketing industry in 2000.
Julie Derry, regional Asia-Pacific director, Microsoft Online Services Group, said: "I would like to thank Grant for working tirelessly over the past five years to grow a strong, successful and sustainable online business for Microsoft in Southeast Asia. We wish him well and look forward to partnering closely with him in his new role."
