DeWit played football in high school and was an all-star quarterback. He was offered a scholarship to the University of Alberta, but decided to quit football after he began learning how to box at a Grande Prairiehealth club which was run by a man named Jim Murrie. Impressed with his dedication and size, Murrie introduced deWit to Dr. Harry Snatic, a dentist and rancher who had been a youth boxing coach in Louisiana before moving his family in 1971 to Beaverlodge, a small town near Grande Prairie. He worked out with deWit three times a week, first in the health club, and then in the deWit's unheated garage where temperatures would often get to 10 or 20 degrees below zero.
Amateur boxing career
DeWit's first fight came at the Alberta provincial championships in March of 1979 in Medicine Hat. Snatic entered deWit in the light heavyweight intermediate novice division for boxers age 17 to 20 with less than 10 fights. DeWit knocked out his first opponent in 20 seconds which caused the coaches of the six other fighters in the division to pull their fighters. DeWit had won his first championship. Snatic then entered Willie in the British Columbia Golden Gloves championships where he fought 18-year-old Shane Anderson who was the western Canadian 178-pound champion and a veteran of about 40 fights. DeWit lost by decision, but he did beat Anderson in two of three return matches. In the last of those bouts, deWit knocked out Anderson, who never fought again. Snatic then took Willie to fight at the Washington State Penitentiary where he knocked out his opponent in the opening minute of the first round. Afterwards in April 1982, Snatic decided to sell his ranch and moved to Calgary. deWit went with him in order to find sparring partners, and to train with a Ugandan exile named Mansoor Esmail, who was Calgary's top boxing coach, and was considered a physical conditioning genius. Willie's first major victory came in Las Vegas in June 1982 when he knocked out Cuba's Pedro Cardenas to win his first North American title. Then he won gold at the Commonwealth Games, taking him a total of three minutes and 12 seconds to knock out three opponents. In March 1983 he defeated Alexander Yagubkin of the U.S.S.R. to win the world title. Then, in September 1983 he defended his North American title against highly touted Cuban Aurelio Toyo. Leading up to the 1984 Olympics, a benefit in Calgary featuring boxing fan Ryan O'Neal and Farrah Fawcett raised $70,000 to finance Willie's training. At this point Snatic began importing professional sparring partners from the United States.
1984 Olympics
At the 1984 Los Angeles Olympics deWit lost the gold medal match in the heavyweight division to Henry Tillman of the United States. Heading into the Olympic Games, deWit and fellow Canadian Shawn O'Sullivan were considered favorites, particularly by Canadian fans and the Canadian media. The Tillman-deWit gold medal final featured no decisive blows, however deWit appeared to win the first two rounds against Tillman with productive work to Tillman's midsection, although Tillman clearly won the third round. Nevertheless, Tillman won by a 5-0 decision. Three of the five judges controversially scored every round for Tillman. The unanimous decision startled Howard Cosell who was calling the bout for ABC Sports. "Good Lord! How do you like that?" Cosell blurted when the decision was announced. During his post-fight interviews, Cosell informed both Tillman and deWit that he personally disagreed with the official verdict. Tillman had also won a controversial decision in his semifinal bout, as had deWit.
Olympic results
1st Round: bye
Round of 16: Defeated Mohamed Boudchiche of Algeria by unanimous decision, 5–0
Quarterfinal: Defeated Dodovic Owiny of Uganda by a first-round knockout
Semifinal: Defeated Arnold Vanderlyde of the Netherlands by split decision, 3–2
Final: Lost to Henry Tillman of the United States by unanimous decision, 0–5
Tabbed early as a "Great White Hope," deWit turned professional immediately, persuaded in part by a contract offer reportedly worth $1 million and began to train out of Burnet, Texas. He then defeated Ken Lakusta to capture the Canadian heavyweight championship. A loss to Bert Cooper in 1987 was deWit's only career defeat, as he retired after six consecutive wins, the last of which being a unanimous decision victory over Henry Tillman.
Retirement and later life
After announcing his retirement he worked and was part owner in a concrete surfacing company in California, which he eventually left to return to Canada. A friend of his who was a judge, suggested he get an education and become a lawyer. DeWit returned to school and graduated from the University of Alberta in 1994 with a law degree. He was appointed Queen's Counsel in 2013 and is the former president of the Canadian Bar AssociationCriminal Law subsection. In 1995 deWit was inducted into the Alberta Sports Hall of Fame. He also has a street named after him in Grande Prairie, Alberta. In 2012, deWit made a cameo appearance in the Calgary-based Souls in Rhythm band's musical video Another Round. In 2017, deWit was appointed as a Justice to the Court of Queen's Bench of Alberta. He sits in Calgary.
