- For the former major league player with a similar name, see Billy Bean.
Beane, who grew up in the San Diego, California area and attended UC San Diego, was a first-round draft choice of the New York Mets in the 1980 MLB amateur draft and played parts of six seasons as a reserve outfielder in the major leagues, with the Mets, the Minnesota Twins, the Detroit Tigers and the Athletics, from 1984 to 1989. He was on the bench for two World Series wins - with the Twins in 1987, and the Athletics in 1989. He completed his 148-game career with a .219 batting average and 3 home runs. Though Beane was a highly touted prospect, his skills in high school did not translate to the Major Leagues.
Beane became GM of the A's in 1997 and since then he has crafted the Athletics into one of the most cost-effective teams in baseball, applying sabermetric principles toward obtaining relatively undervalued players. For example, in 2006 the A's ranked 21st of 30 major league teams in player salaries but had the 5th-best regular-season record. This reflects a typical pattern throughout Beane's stewardship.
Due to his team's success despite its low payroll, Beane was the subject of author Michael Lewis's 2003 best-selling book Moneyball. The book discusses Beane's methods as the GM of the A's and how he used sabermetric principles to run his team in a cost-effective way. According to the book, this allowed him to be successful despite his financial constraints. The book and Beane's methods have influenced the way many think about the game of baseball, including other teams and even players 
Despite this, the Athletics have been repeatedly thwarted in their bid to win in the playoffs under Beane. They finally won a series when they swept the Minnesota Twins in the American League Division Series on October 6, 2006, but were subsequently swept by the Detroit Tigers in the American League Championship Series.
Beane also is a part owner of the A's. On April 15, 2005, Beane received a contract extension to remain with the team as its general manager through 2012, and team owner Lew Wolff awarded Beane a small portion of the team's ownership.
On January 4, 2007, the software company NetSuite named Beane to its board of directors. NetSuite co-founder Evan Goldberg cited Beane's ability to combine facts with instinct as an important factor in the decision to involve him in the company.
When the A's ownership group agreed to purchase the reincarnation of the San Jose Earthquakes of Major League Soccer, Beane, who is an avid supporter of Tottenham Hotspur of the English Premier League, began developing a system for objectively analyzing soccer players. He has agreed to help the Earthquakes front office develop a method for building a cost-effective team, as the salary cap in MLS is even more restrictive than the A's small-market status in Major League Baseball.