Trent McCleary began playing hockey at a very young age and progressed up through the ranks of the Swift Current minor hockey system, starring with the Legionaires. At 16 he was called up for three games with the WHL's Swift Current Broncos. That set the stage for his making the team on a full-time basis in 1989-90. He played in 70 games in his rookie year, scoring three goals and 18 points. Although McCleary never became known for his offensive numbers in junior, he was a tenacious checker and was considered one of the top defensive forwards in the league in his final year with the club in 1992-93 when he suited up as an overage player. The Broncos were the top team in the west and moved on to represent the WHL at the Memorial Cup. They won their opening game against the eventual champions and hosts, the Sault Ste Marie Greyhounds, but three consecutive losses eliminated them from the tournament.
McCleary was not drafted by any NHL team, but he did garner interest from several clubs and was signed as a free agent by the Ottawa Senators in October, 1992. In 1993-94 he played the majority of the year with the Thunder Bay Senators of the old Colonial League. The following year he played with the PEI Senators. In 1995-96 McCleary finally got his opportunity to play in the NHL, skating with the Ottawa Senators in 75 games. That summer he was traded to the Boston Bruins where he played for one year before being released.
McCleary went through a dry spell where he was unable to land a spot in the NHL, so he played in the IHL with the Detroit Vipers and Las Vegas Thunder. He was offered a free agent contract by the Montreal Canadiens in October, 1998 and played with the team for 46 games that year. McCleary's career came to an abrupt end during a game against Philadelphia on January 29, 2000 when he was hit in the throat with a puck. It was later revealed that the shot nearly killed him but the quick work of the on-site medical staff managed to save his life. McCleary had considered a comeback, but realized it was simply not feasible. In 192 NHL games he scored eight goals and 23 points.