The 2011 Los Angeles Angels of Anaheim season was the franchise's 51st season and 46th in Anaheim. The Angels began the season following a disappointing 2010 campaign where they missed the postseason for the first time since 2006, after winning the American League West three times in a row from 2007 to 2009. During the 2011 season, the Angels celebrated the franchise's 50th anniversary and because it was the "golden Anniversary", a gold trim was added to the uniforms including the halo on both the cap and uniform. The date of the franchise's actual 50th anniversary is December 6, 2010. The season saw the debut of Mike Trout, who made his major league debut on July 8, 2011. Although he batted .220 during his brief time on the year, he would be back the following season as the regular fielder for the team.

The Los Angeles Angels are an American professional baseball team based in the Greater Los Angeles area. The Angels compete in Major League Baseball (MLB) as a member club of the American League (AL) West division. Since 1966, the team has played its home games at Angel Stadium in Anaheim, California.