The Boston Celtics have won a total of 18 NBA championships, the most in NBA history. Their titles were won in the years 1957, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1968, 1969, 1974, 1976, 1981, 1984, 1986, 2008, and 2024