Irvine announced his resignation at a hastily convened media conference in Sydney on Wednesday morning.
Glenn Coleman will take over as Sharks chairman.
The Sharks are embroiled in on-going controversy and intense scrutiny with an expansive investigation from Australia's Anti-Doping Authority into possible use of illegal performance enhancing substances.
Sharks management last week stood down head coach Shane Flanagan and at least three other senior playing operations staff as the investigation intensified.
Coleman could not elaborate on expectations through many NRL circles that Flanagan would be reinstated after he was dumped by Irvine and Sharks directors.
Irvine was overseas for almost an entire week as the Sharks crisis escalated last week.
He further fuelled the turmoil when he revealed in media interviews that Sharks players had allegedly been injected with substances used to improve performance in race horses and greyhounds.
He also claimed when dismissing Flanagan and football management and medical staff that any use of injections or suspicious practises were without Sharks board knowledge.
Irvine defended his board of management and decisions taken as the ASADA inquiry continues.
"The board are good people, they're ethical people and they do not deserve the unfair criticism sent their way this week," Irvine said.
"I apologise to them that I wasn't to be able to be here with them during that time."
Irvine made his initial inflammatory comments when en-route back to Australia from an overseas trip and put him at odds with both the rest of the club's board and the playing group.
Board deputy chairman Keith Ward had cited serious management failures when Flanagan was sacked along with long-serving doctor David Givney, football manager Darren Mooney and head trainer Mark Noakes.
Ward said the sackings were not related to any alleged doping practices at the club in the period during the 2011 season that is under investigation.
Irvine claimed in Sunday's interview those stood down or sacked had knowledge of illegal practices for some time but did not inform the board.
Announcing his resignation on Wednesday, Irvine said he should not have made those comments.
"I don't think it did (help). And I'm honest it's been a period of time of extreme pressure and strain for a lot of people," Irvine said.
"That conversation I had I won't back away from it. But it wasn't an interview in a calm situation. It was a middle of the night conversation after quite a bit of badgering. It wasn't sensible to make those comments and I'll take responsibility for those.
"I feel my presence at the club may prove be to an obstacle in allowing those affected by the decisions made by the board last week to move forward.
"As a result I'm standing down as chairman of the board of directors today.
"The club needs some time to investigate and plan the way forward without added distraction.
"There's been ill-informed speculation recently reporting the motivation and reasoning of the board's strong action last Friday.
I want to make something perfectly clear.
"Self interest was the furthest thing from the minds of the directors when they took the tough decisions they took last week.
"I believe we made the right decision for the right reasons."
Additional reporting from AAP.