[3] In 2012, Griffiths coached the Maitland Pickers in the Newcastle Rugby League, as well as mentoring the under-16s New South Wales Koori side.
[2] In April 2022, Griffiths was announced as the head coach of the Newcastle Knights' NRLW team.
[3] The team won 4 of its 5 regular season games, before winning the semi-final match and ultimately winning the 2022 NRLW Premiership, the Knights' defeating the Parramatta Eels 32–12.
[11] On 1 July, the New Zealand Warriors announced the appointment of Griffiths as head coach of their NRLW team, who return to the competition in 2025.
[12] The Newcastle Knights confirmed that Griffiths will depart the club at the conclusion of the 2024 NSW Cup season.