Bill Gates speaking at a press conference at the end of the GAVI Alliance pledging event

William Henry "Bill" Gates III (born October 28, 1955 in Seattle, Washington) is an American business magnate, investor, philanthropist, and author. Gates is the former chief executive officer (CEO) and current chairman of Microsoft, the software company he founded with Paul Allen. He is consistently ranked among the world's wealthiest people and was the wealthiest overall from 1995 to 2009, excluding 2008, when he was ranked third; in 2011 he was the wealthiest American and the second wealthiest person. During his career at Microsoft, Gates held the positions of CEO and chief software architect, and remains the largest individual shareholder, with 6.4 percent of the common stock. He has also authored or co-authored several books.

Gates is one of the best-known entrepreneurs of the personal computer revolution. Gates has been criticized for his business tactics, which have been considered anti-competitive, an opinion which has in some cases been upheld by the courts. In the later stages of his career, Gates has pursued a number of philanthropic endeavors, donating large amounts of money to various charitable organizations and scientific research programs through the Bill & Melinda Gates Foundation, established in 2000.