Webster's first link with the Warriors was in the 2015 and 2016 seasons when he worked with head coach Andrew McFadden.
"Andrew has a great understanding of the Vodafone Warriors from his time here. He truly believes in what our club has, our values, what we stand for and where we can go," Warriors CEO Cameron George said in a statement.
"We're absolutely thrilled to be able to secure a coach of his calibre.
"He has terrific experience at three clubs, not least at the Penrith Panthers where he played such a critical role in helping them to the premiership last season.
"He's extremely well thought of as a coach with a huge future in the NRL and comes highly recommended by Ivan Cleary."
Webster said he's elated about the opportunity to return to Mount Smart Stadium.
"I'm excited and honoured about becoming head coach at the Vodafone Warriors," he said.
"I loved my time in Auckland when I was last there and I'm really looking forward to making it home again.
"I feel we have a real opportunity to progress the club and I can't wait to hit the ground in November."
Most of the roster is already in place for next season, though the incoming coach will have decisions to make on a couple of new recruits.
Webster's arrival will continue a staggering turnover of head coaches at the Warriors. He will be the seventh permanent head coach since 2011 (after Cleary, Brian McClennan, Matt Elliott, McFadden, Stephen Kearney and Brown) while Tony Iro, Payten and Jones have had spells as caretaker coaches.
There is hope that the Webster could be in place for the long term – akin to Cleary – and he will be given time to carve his own niche and turn the ship around.
Shaun Johnson, Jazz Tevaga and Bunty Afoa are the only survivors from when Webster was last at the club, along with Raiders fullback Charnze Nicoll-Klokstad, who has recently signed to return next season.
