Hackett's first management role was Limerick's Thomond College at the age of 20 (1981–1983). As manager of
Leixlip (1983–1985), one of his players was
Jack O'Shea. taking the role at the age of 26.
Westmeath GAA, searching for a manager after the resignation of
Tomás Ó Flatharta, appointed Hackett as senior and under-21 football manager in September 2009, with the choice of someone who had not managed at that level for many years seen as unexpected. Westmeath embarked on a second successive league campaign without winning a game and were
relegated to Division 3 of the National Football League. Hackett resigned in April 2010. He did not contest a single championship match. Hackett later managed the
Kildare minor football team, where his players included the actor
Paul Mescal. He then assisted the
Down senior football team as a psychologist. As the
COVID-19 pandemic emerged in 2020, Hackett was managing the
Ballymun Kickhams footballers. He led that club to the
2020 Dublin Senior Football Championship. In 2022, still managing Ballymun, Hackett was reported to have been interviewed for the
Monaghan senior football team's managerial vacancy that arose following
Séamus McEnaney's departure. ==Personal life==