“I would like to thank the board, players and all staff for their support and commitment during four wonderful years, where I have grown as a coach and a person.”
A Hal KR’s statement, external Read: “After four years as the most successful coach in our modern history and taking us to the pinnacle of the game as world champions, Willie departs with the best wishes of everyone at the club.”
Hull KR retained all four major titles available to Super League clubs after defeating the Brisbane Broncos to win the World Club Challenge in February.
They had gone 40 years without a league title before defeating the Wigan Warriors in the Grand Final in October.
They also won the Challenge Cup and League Leaders Shield for the first time since 1980.
Since last year, Peters has combined his Hull KR job with that of Australia assistant coach.
Last month he said he was interested in taking over as England head coach after Shaun Wayne stepped down.
Hull KR, eighth in the Super League table after five matches this season, face rivals Hull FC on Friday.
