The 42-year-old gave fans some of their most memorable moments, from winning the Irish Cup twice to beating Ole Gunnar Solskjaer’s Molde (with a certain Erling Haaland up front) at Mourneview Park, and recorded four third-placed Premiership finishes.
He ensured the Lurgan-based club finished in the top-seven in 10 of his 11 full campaigns in charge and helped numerous players secure moves across the water.
Here are some of the best moments of Hamilton’s tenure in pictures.
5. Boxing Day glory
Another first - a maiden Boxing Day victory over Portadown. In what is one of the standout days on the Irish League calendar, Gary Hamilton opened the scoring on December 26, 2013 before Rhys Marshall put the hosts 2-0 up. Josh Barton and Darren Murray responded before Mark Patton's 93rd-minute winner gave Glenavon all three points Photo: Tony Hendron/Presseye
6. Booked their spot in the Irish Cup final
An emotional Gary Hamilton celebrates reaching a first Irish Cup final as manager with his grandfather after they defeated Crusaders 3-1. After the score was tied 1-1 following normal time, Ciaran Martyn and Mark Patton scored in extra-time to book Glenavon's spot in the decider Photo: Stephen Hamilton-Presseye
7. Glenavon win the Irish Cup
A landmark moment in Hamilton's managerial reign came in May 2014 when Glenavon defeated Ballymena United 2-1 in the Irish Cup final at Windsor Park. Goals from Kyle Neill and Mark Patton secured a first Irish Cup triumph for the club since 1996/97 Photo: Darren Kidd/Presseye.com
8. Back in Europe
It didn't ultimately end with success, but Hamilton had guided Glenavon to their first European adventure since 2001 when they took on Icelandic outfit FC Hafnarfjordur in July 2014 following that Irish Cup triumph. The overall aggregate score was 6-2 with Glenavon scoring twice away from home - here is Hamilton in action during the Mourneview Park leg Photo: William Cherry/Presseye