Shawn O'Sullivan (born May 9, 1962 in Toronto, Ontario) is a retired Canadian boxer who won gold at the World Amateur Championships in 1981 and the light middleweight silver medal at the 1984 Summer Olympics. He currently lives in Belleville.
O'Sullivan first learned boxing under his father, Michael, a Toronto bus driver. His next teacher was Peter Wylie, a member of the Toronto police department who was a specialist in defusing bombs. He trained at a warehouse in Cabbagetown.
In 1981, O'Sullivan was named the World Amateur Champion and Canadian Athlete of the Year.
Leading up the 1984 Olympics, O'Sullivan and fellow Canadian Willie de Wit were both favoured to win the gold medals in their classes: de Wit as a heavyweight and O'Sullivan as a light middleweight.
In the gold medal bout with Frank Tate, O’Sullivan took Tate to two standing-eight-counts in the second round (and nearly a third as the round ended), but the judges unanimously gave the decision to Tate. O'Sullivan dominated the second round; however, four of the judges (Keith Walker of New Zealand, Han Dong Jin of South Korea, Noureddine Addala of Tunisia and Muili Ojo of Nigeria) gave Tate the round by the slim margin of 20-19.
Tate was booed when the gold medal was draped around his neck. Tate had won in a 5-0 decision and even his coach, Emanuel Steward, admitted O'Sullivan may have won. O'Sullivan, who himself had benefited from a controversial decision against Christophe Tiozzo in the semifinals, was gracious in defeat and called the outcome "unfortunate".
O'Sullivan began his professional career that same year and won his first 11 bouts in the welterweight division. He lost in his 12th fight to future titleist Simon Brown by TKO in the 3rd in 1986 in Toronto's Exhibition Place. O'Sullivan injured his right hand in the first round, and later underwent surgery to repair torn knuckle joints.
O'Sullivan quit boxing in 1988 after consecutive defeats to Luis Santana and Donovan Boucher, but launched a pair of short-lived comebacks in 1991 and 1996. He retired in 1997 with a record of 23-5-0, with 16 knockouts.
Since retiring from boxing, he has been diagnosed with brain damage, as a cumulative result of blows to the head during his boxing career. During an interview, he said that he suffers from boxer's dementia, commonly known as "punch drunk" syndrome.
On February 10, 2010, O'Sullivan carried the 2010 Olympic torch on a stretch through Vancouver. He is currently living in Belleville where he can be seen walking his dog (a boxer) and offering a friendly greeting to fellow dog walkers.