The NRL judiciary decided Hayne, who appeared to aim a headbutt at Slater during his side’s edgy 24-10 win over the Storm, was not guilty of a grade one striking charge.
Hayne will become available for New South Wales in the second Origin match due to be held in Brisbane next Wednesday.
“I’m just very, very happy,” Hayne said after the hearing.
“It had pretty much rattled me and I’m just so excited to be part of the squad now.
“It happened so fast – it felt like I was in there for a whole game it happened so quick.
“I’m just really, really excited and I just cannot wait to see the boys.
“I just didn’t want to think about it. I had great lawyers and great people behind me and represented me very well.
“State of Origin is such a massive thing so I’m glad I can be a part of it.”