Fitzwilliams began playing football at the youth level with St Clair Coaching School in his native Trinidad.

He helped Mississauga secure a postseason by recording the winning goal against Hamilton Thunder in a 3-2 victory.

[9] He participated in the 2003 Open Canada Cup where he contributed a goal against St. Catharines in the semifinal and advanced the Lions to the final.

[32] The 2011 season proved would be a notable one for the midfielder as he provided goals against Mississauga Eagles and York Region Shooters in the opening rounds of the playoffs.

[33] As a result, the Croats reached the championship final where Fitzwilliams scored the single winning goal against Capital City.

[34] He added more silverware to his portfolio in 2012 by claiming the double with Toronto, by winning the First Division title, and his third CSL Championship.

[40] Fitzwilliams made his national team debut on March 26, 2003 in a CONCACAF Gold Cup Qualifier match against Antigua and Barbuda.

[42][43] He played against Dominican Republic on June 13, 2004, in the 2006 FIFA World Cup qualification – CONCACAF second round.