Tonga coach Kristian Woolf has been appointed by St Helens as the successor to Justin Holbrook.
Woolf, who finished the NRL season as caretaker boss of Newcastle Knights, will take up a two-year contract as Saints' new head coach on November 1.
St Helens chairman Eamonn McManus said: "We consider that Kristian is ideally qualified and placed to build upon the current success of the team and the club."
In appointing the 44-year-old Woolf, Saints are continuing a growing trend of Super League clubs opting for assistant coaches in the NRL.
Trent Robinson and Michael Maguire achieved their mark in Super League with Catalans Dragons and Wigan respectively before landing top jobs in the NRL and Holbrook has followed suit.
McManus added on Woolf: "He has the experience and expertise to bring the best out of our existing squad and to improve it further.
"We are very confident that the Saints will seriously compete for honours under his tenure and that we will continue to play attractive and exciting rugby league."
Woolf has been assistant at Brisbane, North Queensland Cowboys and Newcastle and famously guided Tonga to the semi-finals of the 2017 World Cup in which they suffered a 20-18 defeat to England.
Woolf said: "I'm excited and privileged to be joining St Helens as head coach. It's something I have always wanted to do and it's a great opportunity for me.
"St Helens is a club with an amazing history and I'm confident we can achieve great things together."