A swingman, Havlicek played collegiate basketball for the Ohio State Buckeyes from 1959 to 1962, winning an NCAA championship in 1960.

[citation needed] Havlicek was named as an alternate of the 1960 United States national team that competed in the 1960 Summer Olympics.

In the seventh and final game, played at Boston Garden on April 15, the Celtics led the Philadelphia 76ers 110–109 with five seconds left.

They only needed to inbound the ball from underneath their basket to secure the victory and advance to the 1965 NBA Finals.

However, Bill Russell's pass struck one of the basket's support wires hanging down from the ceiling, leading to a turnover that gave the 76ers and Wilt Chamberlain the ball and a chance to win the game.

[17] In Game 5 of the 1968 Eastern Division Finals, Havlicek recorded a near triple-double with 29 points, nine rebounds, and 10 assists as the Celtics avoided elimination at the hands of the 76ers.

[25] "'On stamina alone, he’d be among the top players who ever played the game,' longtime New York Knicks coach Red Holzman once said of John “Hondo” Havlicek.

God had to compound it by making him a good scorer, smart ballhandler and intelligent defensive player with quickness of mind, hands and feet'".

[9][23] As of 2019, only Bill Russell (with 11) and Sam Jones (with 10)--both of whom were Celtics teammates of Havlicek's--had won more NBA championships than he had.

[38] In October 2021, Havlicek was again honored as one of the league's greatest players of all time by being named to the NBA 75th Anniversary Team.

[41] Fellow NBA Hall of Famer Chris Mullin wore number 17 as a tribute to Havlicek.

[44] In addition to his on-court success, Havlicek was known for his character[45][46] and for his commitment to placing the team ahead of his own individual achievements.

[46] Havlicek was shrewd with his money during his playing career, and he invested much of this income in the Wendy's fast food chain during its formative years.

The success of his investments left Havlicek with a comfortable income after retirement and he never had to work for a conventional salary again.

[1] Havlicek was a member of the board of the Genesis Foundation, which assists children with disabilities and genetic disorders.

He and his wife Beth held the John Havlicek Celebrity Fishing Tournament for more than three decades, with proceeds going to the foundation.

[48] Jill Havlicek married former Major League Baseball outfielder and coach Brian Buchanan.