Brian Patrick Wilson (born March 16, 1982), nicknamed "the Beard" and "B-Weezy", is an American former professional baseball relief pitcher. He played in Major League Baseball (MLB) for the San Francisco Giants and Los Angeles Dodgers. He stands 6 feet 1 inch (1.85 m) tall and weighs 205 pounds (93 kg). Wilson is known for his large black beard, which he began growing during the 2010 pennant race. Wilson's entrance at home games accompanied by the song "Jump Around" was popular with fans.

Wilson pitched collegiately at Louisiana State University. His college career ended during his junior season, when he injured his elbow and underwent Tommy John surgery. The San Francisco Giants selected him in the 2003 draft. He reached the major leagues in 2006 and had become the Giants' regular closer by the end of 2007. In 2010, he led the Majors with 48 saves, tying the franchise single-season record, while posting a 1.81 ERA, and he saved clinching games at every level of the playoffs, including the 2010 World Series over the Texas Rangers.

In the first week of the 2012 season, Wilson injured his elbow and subsequently underwent his second Tommy John surgery. He completed his recovery midway through the 2013 season and signed with the Los Angeles Dodgers, pitching effectively with them as a late-inning reliever through the playoffs. However, he was not able to continue his success in 2014, and the Dodgers released him after that season.

Brian Patrick Wilson was born on March 16, 1982, in Winchester, Massachusetts. While he was in second grade, he moved to Londonderry, New Hampshire. Today, he talks little of his childhood except to discuss his father, Mike Wilson, who was an Air Force veteran and a demanding perfectionist. During fall, he would have Brian bag leaves and bury them in the woods; and in winter, he would have Brian spend seven hours shoveling snow on weekends. Brian said in a 2011 interview, "I think that's how you need to be raised. It's not your friend, it's your dad. And he's going to be strict. And one day you're going to understand why. And sometimes, it's a little too late. They might pass away, and you might not get that chance to say thanks or understand why you did those things. But when you become a man, you understand why."

When Wilson was 12 years old, his father was diagnosed with cancer. His father fought the disease for five years before dying while Wilson was attending Londonderry High School; Wilson today says he had to become a man when his father was diagnosed. In a 2011 story, ESPN.com writer Elizabeth Merrill said about Wilson's high school years, "He was an honor roll student at Londonderry, but clashed with various authority figures who didn't appreciate his occasional lack of a filter." In the same story, a number of Londonderry faculty speculated that some teachers didn't understand Wilson's life situation at the time. Art Psaledas, an assistant principal at the school, added, "It happened at probably the worst time anybody could lose your dad. Watching his dad deteriorate over the years was probably the singular thing that formed his personality."

Bob Napolitano, Wilson's coach at Londonderry High School, noticed Wilson's ability to concentrate on baseball. Napolitano specifically remembered the first home game of Wilson's senior year, which happened shortly after his father's death. No fewer than 29 professional scouts, all with radar guns, showed up to see him pitch. According to Napolitano, Wilson was completely oblivious to their appearance; he ate and drank in the dugout, warmed up, and pitched a two-hitter while apparently not noticing that scouts were there. The Cleveland Indians offered him a contract straight out of high school, but he did not sign, opting to attend college instead.

After a coach saw Wilson pitch well at a tournament in California, he was offered a scholarship to Louisiana State University (LSU), where he played for the LSU Tigers baseball team, eventually becoming their No. 2 starter. In his time at LSU, Wilson pitched in 51 games (22 starts) and accumulated 18 wins, 10 losses, and five saves. In 2002, he played collegiate summer baseball with the Hyannis Mets of the Cape Cod Baseball League. He was in the middle of his third season on March 28, 2003, when he injured his elbow and underwent Tommy John surgery. He also played for the Keene Swamp Bats of the New England Collegiate Baseball League, a summer league for collegiate prospects. Despite facing extensive rehabilitation, Wilson chose to enter the 2003 Major League Baseball draft.

Coming off his surgery, Wilson was drafted by the San Francisco Giants in the 24th round in 2003. He began his career with the Hagerstown Suns of the Class-A South Atlantic League in 2004. In 23 games, he had a 2–5 record, a 5.34 earned run average (ERA), 41 strikeouts, and 22 walks in 57+1⁄3 innings pitched. He made three starts that year, the only time he ever started games professionally. The Giants switched single-A affiliates the next year and Wilson began pitching for the Augusta GreenJackets. In 26 games, he had a 5–1 record, a 0.82 ERA, 30 strikeouts, and seven walks in 33 innings pitched while notching 13 saves, good for second in the league behind Brett Campbell's 19. His performance with Augusta caused Mark Camps of the San Francisco Chronicle to mention him in his "Minor Report" on May 15. He also pitched for the Norwich Navigators of the double-A Eastern League (posting no record, eight saves, a 0.57 ERA, 22 strikeouts, five walks, and 15+2⁄3 innings pitched in 15 games) and the Fresno Grizzlies of the Triple-A Pacific Coast League (posting a 1–1 record, no saves, a 3.97 ERA, 13 strikeouts, eight walks, and 11+1⁄3 innings pitched in nine games).