Lazarus achieved a formidable reputation in prop forward position at club, state (NSW), and international levels. He was the first player in the history of the game to win premierships with three different clubs: Canberra Raiders, Brisbane Broncos and Melbourne Storm. Lazarus was also named Players' Player for two consecutive Kangaroo Tours: 1990 and 1994. In addition, Lazarus scored the first ever rugby league try at the MCG during a State of Origin game.
Lazarus played for the Broncos at prop forward in the 1993 grand final victory again over the St. George Dragons. This constituted a remarkable feat of playing in five consecutive grand finals. During the 1994 NSWRL season, Lazarus played at prop forward for defending premiers Brisbane when they hosted British champions Wigan for the 1994 World Club Challenge and lost. He was selected to go on the 1994 Kangaroo Tour, although his appearances were restricted due to injuries. It was only a broken (dislocated) ankle suffered during a 1997 World Club Championship match that prevented Lazarus from also playing in that year's Super League grand-final-winning Brisbane side.
Lazarus was recruited to the newly established Melbourne Storm by his former CEO (John Ribot) and teammate (Chris Johns) from the Broncos, both then working in the Storm's administration, for the National Rugby League's inaugural season in 1998. He was named as the club's first captain and was also given a newspaper column to write in The Herald Sun. He went on to lead the Melbourne Storm at prop forward in their 1999 grand final victory. Lazarus announced his retirement from the game with five premierships for three different clubs (Canberra 1989–90, Brisbane 1992–93 and Melbourne 1999), a unique achievement.
In 2000, Lazarus was awarded the Australian Sports Medal for his contribution to Australia's international standing in rugby league. In 2003, he was one of the first four former players inducted into the Broncos' official Hall of Fame. In 2005, the western grandstand of Olympic Park Stadium was named the Glenn Lazarus stand in his honour. Lazarus spent time on the Brisbane Broncos coaching staff until a major cleanout by head coach Wayne Bennett at the end of 2005 saw him removed.
In February 2008, Lazarus was named in the list of Australia's 100 Greatest Players (1908–2007) which was commissioned by the NRL and ARL to celebrate the code's centenary year in Australia. Lazarus has been 612 ABC Brisbane Breakfast rugby league tipster since 2008. In 2008 New South Wales announced their rugby league team of the century, naming Lazarus at prop.
Lazarus was selected to head the Palmer United Party (PUP) Senate ticket in Queensland at the 2013 federal election and was elected on a 9.89 percent primary vote. He got to the required 14.3 percent quota from a favourable preferential tally from group voting tickets. His term as a PUP senator commenced on 1 July 2014 and became PUP senate leader.
He announced his resignation from PUP through Facebook on 13 March 2015 and became an independent senator. He wrote: "I have a different view of team work. Given this, I felt it best that I resign from the party and pursue my senate role as an independent senator."