Terence Joseph James "Terry" O'Reilly - Born June 7, 1951 in Niagara Falls, Ontario is a Canadian retired ice Hockey right winger and coach.

O'Reilly played his junior Hockey with the Oshawa Generals in the Ontario Hockey Association / OHA from 1968 to 1971.

The Boston Bruins drafted him 14th overall in the 1971 NHL Amateur Draft.

O'Reilly played his first year of pro Hockey with the Bruins affiliate, the Boston Braves of the American Hockey League / AHL during the 1971-72 season, scoring 9 goals, 8 assists. He also made his NHL debut for the Bruins, playing in 1 game, in which he scored his 1st NHL goal.

O'Reilly started the next season with the Bruins and remained a fan favourite for the next 13 years with his hard nose style of playing.

O'Reilly was known for being a tough player, racking up over 200 penalty minutes in five consecutive seasons, and earning for himself the nickname "Bloody O'Reilly" in the press. His teammate, Phil Esposito, dubbed O'Reilly "Taz" in reference to the Tasmanian Devil cartoon character for O'Reilly's reckless, hard driving style of play. The tenacious winger hit the 20-goal mark four times and helped the Bruins reach the Stanley Cup final and semi-finals three times each. He often formed an effective team with centre Peter McNab and various left-wingers such as John Wensink and Al Secord.

On top of his physical presence, he also had a decent scoring touch, highlighted by his 29-goal, 90-point season in 1977–78. He added to that with a 77-point (26 goals) effort the following campaign. He had 211 and 205 minutes in penalties in those seasons respectively, displaying an excellent balance of grit and scoring. O'Reilly was also chosen to play in the 1975 and 1978 NHL All-Star games.

O'Reilly also made the NHL history records, when on December 23, 1979, at Madison Square Garden, during a post-game scrum, John Kaptain, a New York Rangers fan used a rolled-up Hockey program and smacked Bruins player Stan Jonathan in the face drawing blood, and then stole his stick and wielded it like a weapon. O'Reilly scaled the glass boards and charged into the stands grabbing Kaptain. His teammates followed when other fans tried to intervene. O'Reilly was suspended eight games and fined $500. The brawl remains one of the most memorable fan-athlete confrontations in sports.

Terry O'Reilly was very protective of his teammates. When the Bruins retired O'Reilly's No. 24, Ray Bourque noted that O'Reilly's banner "hangs next to mine, protecting me again.

O'Reilly was also suspended by the NHL for first 10 games of 1982-83 season for assault on referee Andy Van Hellemond, April 25, 1982.

O'Reilly was named the Boston Bruins captain for the 1983-84 season, and would retire after the 1984-85 season as the Bruins captain.

O'Reilly played his entire NHL career with Boston, scoring 204 goals, 402 assists and 2095 penalty minutes in 891 regular season games, and 25 goals, 42 assists and 335 penalty minutes in 108 playoff games.

O'Reilly was soon hired as Boston's assistant coach and became the replacement head coach of the Bruins during the 1986–87 NHL season. In 1987-88, he led the Bruins to only their third playoff win against the Montreal Canadiens in 22 series on the way to reaching the 1988 Stanley Cup Final. After one more season with the club, O'Reilly stepped down from his post as the Bruins' coach in order to spend more time with his son who was seriously ill with liver disease. As coach, O'Reilly posted a 115-86-26 record.

O'Reilly also was an assistant coach for the Rangers for the two seasons prior to the NHL lockout.

In the Adam Sandler movie Happy Gilmore, O'Reilly is mentioned as Happy Gilmore's favorite Hockey player growing up because of his tough style.

The Boston Bruins retired O'Reilly's No. 24 on October 24, 2002.