Denis Hamel was born May 10, 1977 in Lachute, Quebec. The sixth round, 153rd overall selection of the St. Louis Blues in the 1995 NHL Entry Draft, Hamel is a graduate of the QMJHL's Chicoutimi Sagueneens.
An offensively gifted forward, Hamel played three seasons in Chicoutimi, registering 100 points (50-50-100) in his final year. In March of 1996, Hamel had his NHL rights traded to the Buffalo Sabres and in the fall of 1997 made his professional debut with the club's AHL affiliate in Rochester.
After playing the better part of three seasons in Rochester, Hamel went on to make his NHL debut during the 1999-00 season. Over the course of the next three seasons, Hamel became a regular in the Buffalo lineup before opting to sign as a free agent with the Ottawa Senators in the summer of 2003. Having yet to play a game with the Senators, Hamel was put on waivers and claimed by the Washington Capitals just prior to the 2003-04 season, before being re-claimed by the Senators a mere two days after the Caps had acquired him.
In his first full season with the Senators organization, the former Chicoutimi star went on to spend the majority of his season with the club's AHL affiliate in Binghamton.
After suiting up for 43 games the Ottawa Senators in the 2005-06 season, the club placed Hamel on waivers. The following day Hamel was claimed off waivers by the Atlanta Thrashers. After only three games with the Thrashers, Hamel was again placed on waivers and was shortly after claimed by the Philadelphia Flyers. Hamel spent seven games with the Flyers and was left without a contract in the summer of 2007 until the Senators opted to sign their former teammate in July.