Steven Anthony Ballmer (born Detroit, Michigan March 24, 1956) is an American businessman who has been the chief executive officer of Microsoft Corporation since January 2000. Ballmer is the second person after Roberto Goizueta to become a billionaire in U.S. dollars based on stock options received as an employee of a corporation in which he was neither a founder nor a relative of a founder. In Forbes 2008 World's Richest People ranking, Ballmer was ranked the 43rd richest person in the world, with an estimated wealth of $11 billion.

Ballmer was born in Detroit. On October 4, 2007, Ballmer was awarded honorary citizenship of Lausen, Switzerland. His father had worked in Belgium as a manager at Ford Motor Co in the 1960s. In 1990 Ballmer married Connie Snyder, who was on Microsoft's PR team at the Waggener Group in the '80s. They have three children. Ballmer's maternal grandparents lived in Pinsk, Belarus.

Steve Ballmer was born March 24, 1956, to a Swiss father and a Jewish-American mother whose family came from the Eastern European city of Pinsk (today in Belarus). It has been reported that Ballmer belongs to Mensa and has an IQ of over 135. He grew up in Farmington Hills, Michigan. In 1973, he graduated from Detroit Country Day School, a high school, and now sits on its board of directors. In 1977, he graduated from Harvard University with a bachelor’s degree in mathematics and economics. While in college, Ballmer managed the football team, worked on The Harvard Crimson newspaper as well as the Harvard Advocate, and lived down the hall from fellow sophomore Bill Gates. He then worked for two years as an assistant product manager at Procter & Gamble, where he shared an office with Jeffrey R. Immelt, who would later become CEO of General Electric. In 1980, he dropped out from the Stanford University Graduate School of Business.