Iro had been with the Warriors since 2005 and coached the Junior Warriors in the inaugural Toyota Cup competition in 2008 before stepping up to assist Cleary in 2010. He took over as caretaker coach when McClennan was sacked with two games remaining this season.
He has also worked as Kiwis assistant since 2009.
Iro said the decision was a difficult one.
"After so long here, I had a lot to weigh up," he said.
"The Vodafone Warriors gave me the chance to start my coaching career. I've had plenty of great times with the club and I've learnt so much.
"I'm grateful for the chance I was given to start my coaching career here but I've decided to move on to explore other opportunities. I want to thank all the coaching staff, players past and present and staff I've enjoyed working with."
Vodafone Warriors chief executive Wayne Scurrah said the club had been keen for Iro to continue in the role he has filled with the NRL side for the past three seasons.
"Tony has made a major contribution since joining our football department in 2005, most recently with our NRL side," he said.
"It's disappointing he won't be staying on but we gave him time to make his decision and respect the choice he has made.
"We're extremely grateful for what Tony's done for the Vodafone Warriors. He is looking at other opportunities and we wish him and his family all the best for the future."
