Lewis is a 25-year veteran of Microsoft, joining the firm in 1989, and has led the Xbox business since it started and held various sales and marketing roles.
He officially leaves in the coming weeks as the company seeks a replacement. He is moving on to focus on his own business interests.
Lewis was part of the team that made Xbox 360 the UK's biggest games console over the last generation, and oversaw the tricky launch of Xbox One. We last spoke to him in September.
During his career, he's picked up numerous awards, and in 1999 picked up the EMEA Chairman’s award for outstanding leadership and consistent business success from Bill Gates.
“Since joining Microsoft as one of the first UK employees in 1989, Chris has made significant contributions across the partner, enterprise and retail businesses," said CVP of Microsoft's devices and studios marketing group Yusuf Mehdi.
"He has been a distinguished leader for our Xbox team in Europe – overseeing the launch of the original Xbox, Xbox 360, Kinect and most recently Xbox One, and growing the business significantly across the region."
“Following that success, Chris has now chosen to retire from Microsoft and focus on his other business and personal interests. We wish Chris nothing but the best, and we thank him for everything he’s contributed to Xbox and Microsoft as a whole over the past 25 years.”