William Henry Gates III (born October 28, 1955) is an American business magnate, software developer, investor, and philanthropist. He is best known as the co-founder of Microsoft Corporation. During his career at Microsoft, Gates held the positions of chairman, chief executive officer (CEO), president and chief software architect, while also being the largest individual shareholder until May 2014.

He is one of the best-known entrepreneurs and pioneers of the microcomputer revolution of the 1970s and 1980s.

Born and raised in Seattle, Washington, Gates co-founded Microsoft with childhood friend Paul Allen in 1975, in Albuquerque, New Mexico; it went on to become the world’s largest personal computer software company.

Gates led the company as chairman and CEO until stepping down as CEO in January 2000, but he remained chairman and became chief software architect.

Since 1987, he has been included in the Forbes list of the world’s wealthiest people. From 1995 to 2017, he held the Forbes title of the richest person in the world all but four of those years.

In October 2017, he was surpassed by Amazon founder and CEO Jeff Bezos, who had an estimated net worth of US$90.6 billion compared to Gates’ net worth of US$89.9 billion at the time. As of November 2019, Gates had an estimated net worth of US$107.1 billion, making him the second-wealthiest person in the world, behind Bezos.