The Boston Celtics are an American professional basketball team based in Boston, Massachusetts. The Celtics compete in the National Basketball Association (NBA) as a member of the league's Eastern Conference Atlantic Division.
Founded in 1946 as one of the original eight NBA teams to survive the league's first decade, the team is owned by Boston Basketball Partners LLC. The Celtics play their home games at the TD Garden, which they share with the National Hockey League (NHL)'s Boston Bruins.
The franchise is the most successful in NBA history, with 17 championships, which accounts for 24.3 percent of all NBA championships since the league's founding. As a percentage of championships won, the Celtics are the most successful franchise to date in the major four traditional North American professional sports leagues.
The Celtics have a notable rivalry with the Los Angeles Lakers, and have played the Lakers a record 12 times in the NBA Finals, including their most recent appearances in 2008 and 2010, where the Celtics have won nine meetings. Four Celtics players (Bob Cousy, Bill Russell, Dave Cowens and Larry Bird) have won the NBA Most Valuable Player Award for an NBA record total of 10 MVP awards. Both the nickname "Celtics" and their mascot "Lucky the Leprechaun" are a nod to Boston's historically large Irish population.
After winning sixteen championships throughout the 20th century, the Celtics rose again after struggling through the 1990s to win a championship in 2008 with the help of Kevin Garnett, Paul Pierce, and Ray Allen in what was known as the new "Big Three" era, following the original "Big Three" era that featured Larry Bird, Kevin McHale, and Robert Parish, which combined to win the 1981, 1984, and 1986 championships.
Following the win in 2008, general manager Danny Ainge began a rebuilding process with the help of head coach Brad Stevens, who led the Celtics to a return to the playoffs from 2015. During the following season, the Celtics clinched the top seed in the Eastern Conference, and eventually reached the Conference Finals prior to losing to the Cleveland Cavaliers in five games.