A native of Buffalo, New York, Todd Marchant excelled with the Niagara Scenics of the NAJHL before spending two years at Clarkson University. After scoring 46 points in 33 games for the Golden Knights in 1992-93, he was voted to the ECAC Second All-Star Team and was selected 164th overall by the New York Rangers in the 1993 NHL Entry Draft. The speedy forward committed to the U.S. national program in 1993-94 and played at the Lillehammer Olympics.
The talented pivot played one game for the Rangers after the Olympics and was dealt to the Edmonton Oilers for Craig MacTavish just prior to the March deadline. Marchant spent the lockout portion of the 1994-95 season with the AHL's Cape Breton Oilers before scoring 27 points in 45 games as an NHL rookie. Over the next few seasons, he became a fixture in the Edmonton line up with his speed symbolizing the crux of the team's improvement.
In 1996-97, Marchant helped the Oilers qualify for the post season for the first time since 1992. He also provided the overtime winner in the seventh game of the club's first-round upset victory over the Dallas Stars. Over the years Marchant proved to be one of the more durable player for the Oilers and during the 2002-03 season he hit the 20-goal plateau for the first time while establishing career highs also in assists with 40 and points with 60.
After ten seasons with the Oilers, the former Clarkson standout signed as a free-agent with the Columbus Blue Jackets in the summer of 2003 and went on to play one full season with the club before being acquired by the Anaheim Mighty Ducks in the early stages of the 2005-06 season. Upon his arrival in Anaheim, Marchant guided the Ducks to a 36-17-8 record and led the club in assists in the 2006 playoffs. A pair of unrelated injuries left Marchant out of the Ducks line-up for 23 regular season and 10 playoff games in 2006-07. When he returned in the playoffs, Marchant helped the Ducks to their first ever Stanley Cup championship.
Aside from his Olympic experience in 1994, Marchant represented his homeland at the 1993 World Junior Chamiponship.