The 1956–57 Boston Celtics season was the 11th season for the franchise in the National Basketball Association (NBA). This was the first time in franchise history where the Celtics advanced to the NBA Finals, which they won over the St. Louis Hawks in 7 games. The Celtics would make the Finals a record 10 consecutive seasons, spanning from this season to the 1965–66 season. They were led by 1957's MVP Bob Cousy, as well as Bill Russell, Bill Sharman, and 1957's Rookie of the Year Tom Heinsohn.

Robert Joseph Cousy is an American former professional basketball player. He played point guard for the Boston Celtics from 1950 to 1963, and briefly with the Cincinnati Royals during the 1969–70 season. A 13-time NBA All-Star and 1957 NBA Most Valuable Player (MVP), Cousy was a core piece during the early half of the Celtics dynasty winning six NBA championships during his 13-year tenure with the Celtics. Nicknamed "The Houdini of the Hardwood", Cousy was the NBA assists leader for eight consecutive seasons, introducing a new blend of ball-handling and passing skills to the NBA. He is regarded as the first great point guard of the NBA, and was the first to reach the 4,000, 5,000, and 6,000 career assists milestones.