Coach Ron Griffiths will leave Newcastle's NRLW side after two premierships to take charge of the men's NSW Cup team.
The Knights have not yet announced Griffiths' successor as the NRLW team lays plans for a third consecutive title.
Newcastle believe the move is in the best interest of progressing Griffiths' career as a coach.
"Ronald has done an outstanding job as NRLW head coach, and we felt coaching NSW Cup was the next phase in his coaching career," said head of football Peter Parr.
Griffiths alluded to the possibility of stepping down after the Knights beat Gold Coast last month to claim a second premiership.
He met with club management in the lead-up to the grand final to gauge his interest in changes to his position.
"Coaching NSW Cup will be an exciting opportunity," Griffiths said on Thursday.
"The Knights have afforded me the chance to be a part of a history-making NRLW team, I will be forever grateful for those opportunities and the memories created."
After a last-placed finish in 2021, Newcastle appointed former Wests Tigers assistant Griffiths as head coach and he oversaw rapid improvement across his two seasons in charge.
The club recruited such superstar players as Tamika Upton and Millie Boyle under his watch and debuted Jesse Southwell, who has gone on to become a leading light in the NRLW.
The Knights' NSW Cup team finished second-last in 2023 with eight wins from 24 games.