Mike Grier was born January 5, 1975 in Detroit, Michigan. The ninth round, 219th overall selection of the St. Louis Blues in the 1993 NHL Entry Draft, Grier is a graduate of the Boston University Terriers.
The hulking forward joined BU in 1993-94 after spending the previous year with St. Sebastian's of the USHS. In his three seasons with the Terriers (1993-1996), Grier registered 59-61-120 in 114 games and was instrumental in leding BU to its fourth NCAA championship in 1995. In 1994-95, Grier earned several honours as he was a Hobey Baker Award finalist, was named to the NCAA East First-All America Team and the Hockey East First All-Star Team and won the Gridiron Club of Boston's Walter Brown Award as the top American-born player in New England.
A member of back-to-back Hockey East conference championship teams with BU in 1993-94 and 1994-95 Grier was also a member of Team USA at the 1995 World Junior Championships.
In the summer of 1995 the Edmonton Oilers acquired goaltender Curtis Joseph and and prospect Mike Grier from the St. Louis Blues. After a strong career at BU Grier made his professional debut with the Edmonton Oilers in 1996-97 and led all Oiler rookies in scoring with 15-17-32 and was ninth in scoring among NHL rookies. In 1998-99, Grier was awarded the Oilers "Unsung Hero" Award as he enjoyed the most productive season on his young career, finishing the year with 20-24-44 in 82 games.
Grier went on to play six seasons with Oilers before he was traded to the Washington Capitals prior to the 2002-03 season. Upon his arrival in Washington, the former BU Terrier registered 32 points (15-17-32) in his first full season with the club, however, Grier and the Caps struggled in 2003-04 and with the team dumping salary, Grier was subsequently dealt to the Buffalo Sabres at the trading deadline. After failing to qualify for the post season, Grier joined Team USA at the 2004 World Championships in Prague, Czech Republic and was instrumental in helping them capture the bronze medal.
Following his stint with the Sabres, Grier was signed in the summer of 2006 by the San Jose Sharks as a free agent.
In the summer of 2009, after three seasons on the west coast, Grier re-joined the Sabres, signing as an unrestricted free agent.