The Broncos today announced that Griffin’s tenure had been extended for another two years to include the 2014 and 2015 seasons.
He had already been contracted until the end of next year.
Griffin began his tenure at the Broncos as NYC coach in 2008, the first year of the under-20 competition, taking them to the grand final.
He made the preliminary final the next year with that squad before becoming assistant coach of the NRL team in 2010.
Griffin took over the NRL head-coaching role in February last year and led the Broncos to the preliminary final, losing to eventual premiers Manly. He has amassed a 31-13 win-loss record in that time.