Toronto, which traded for center Owen Nolan from San Jose on Wednesday, sent a second-round pick in the 2004 draft to the Carolina Hurricanes for Wesley.
Wesley, 34, has one goal and seven assists in 40 games this season. He collected 47 goals, 143 assists and 434 penalty minutes in 629 games with the Hurricanes, which ranks third on the franchise's all-time list.
Wesley collected two assists in 22 playoff games last season, when the Hurricanes reached the Stanley Cup Finals for the first time ever. He spent seven seasons with the Boston Bruins prior to being traded to the Hartford Whalers for three first-round picks in August 1994 and has 124 goals, 373 assists and 855 penalty minutes in 1,166 career games.
Toronto, which lost in six games to Carolina last May in the Eastern Conference finals, is fifth in the East. Nolan made his debut with the Leafs on Saturday and scored twice in a 3-3 tie with Vancouver.
The Hurricanes have won their last two games, but are only one point ahead of last-place Atlanta in the East. Last month, Carolina dealt right wing Sami Kapanen to Philadelphia and placed goaltender Arturs Irbe on waivers. Irbe cleared waivers and spent time in the minor leagues before being recalled.
The NHL trade deadline is Tuesday.