Crowe began his career with local Irish side St Mochta's, joining the youth setup at the age of 7. Stella Maris showed an interest in Crowe for several years and he eventually signed for the club and played in the Dublin & District Schoolboy League.[2] At the age of 17, Crowe spent time on trial with Division One side Wolverhampton Wanderers, attending three separate trials with the club before being offered a one-year YTS contract. He spent the majority of his first season at Molineux in the youth team but was handed his professional debut on 30 April 1996 as a substitute during a 3–0 defeat to Reading. In the following match, the final game of the 1995–96 season, Crowe started his first match for Wolves against Charlton Athletic in May 1996 and scored his side's only goal during a 1–1 draw.[2] He had loan spells at Cardiff City, Exeter City and Plymouth Argyle.
After scoring on his League of Ireland debut on 19 September 1999 in a 3–1 loss to Shamrock Rovers[1], Crowe ended up as top scorer for Bohemians in his first season with 9 league goals. The following season (2000/01), Glen formed a potent partnership with new-signing Trevor Molloy and broke the League goal-scoring record by hitting 25 league goals (35 in all competitions) as Bohemians won their first league title since 1978 and their first league and FAI Cup double since 1928. He also scored in Bohemians' UEFA Cup run, both home and away against 1. FC Kaiserslautern. This form led Mick McCarthy to call him into the international squad in the summer of 2001 for the World Cup qualifiers against Portugal and Estonia.
Crowe once again starred as Bohemians won their 2nd league title in 3 years in 2003, but left the team for Dublin rivals Shelbourne in a controversial move in December 2004 where he formed a successful partnership with Jason Byrne. He claimed his third league winning medal in November 2006, ironically scoring the winning goal against his old club Bohemians to clinch Shelbourne's third title in four seasons.
Crowe re-joined Bohemians in early 2007 where he continued to show his goalscoring skills. On 4 April 2008, he broke the previous record of 121 goals against Shamrock Rovers to surpass the record previously held by Turlough O'Connor.[3] Bohemians romped to the 2008 Premier Division title by 19 points from their nearest challengers St Patrick's Athletic, and Crowe also scored in the FAI Cup Final as Bohemians won the trophy to complete a "Double".[4] He scored against Rhyl F.C. in the 2008 UEFA Intertoto Cup[2].
Crowe struggled for form during the 2009 season and found himself out of the starting XI on many occasions when Paddy Madden returned from his loan spell at Shelbourne. However Glen collected his first ever League Cup winners medal in the September as Bohemians beat Waterford United 3–1 at the RSC.[5] And Crowe collected his fifth League winners medal (fourth at Bohemians) in November as they won the title.[6]
Sporting Fingal
Crowe was released by Bohemians in November 2009 after his contract expired. In January 2010, he signed for Sporting Fingal in advance of the club's first season in the League of Ireland top flight.[7]