Granger leveled the accusations on Tuesday after Noah helped the Bulls eliminate the Pacers from a chippy first-round series.
"I don't know Danny Granger at all, but I do know Joakim, and I do not agree with that one bit," Donovan said Thursday on "The Waddle & Silvy Show" on ESPN 1000. "Jo to me is the guy that I've got a tremendous amount of love and affection for.
"He's one of those guys, that I think if you're the opposing team, you don't like him."
"I went through it with [Noah] in college in his sophomore year, he kind of hit the NCAA tournament like a lightning rod," Donovan said. "Everyone was kind of like 'Who is this guy in the pony tail beating his chest,' and the enthusiasm, the excitement.
"And then going into his junior year, after making the decision to come back to school, there were a lot of people who didn't like all his antics and the way he played, and all the chest pounding and bumping and the intensity. He's one of those guys where if he's on your team, you absolutely love him because he's a great kid, he's a great teammate, he's all about winning, and what you see on the floor with him is what you get when nobody's looking."
Noah won two titles with the Gators, and Donovan praised Noah's passion and aggressiveness.
"I think the last thing I would say about him is that he is a dirty player, that's the farthest thing from the truth, but again, I don't know Danny Granger," Donovan said. "I don't know what the intent was of that, but I'll tell you this, when you go against Joakim, you better bring it, because he is coming every single possession for every offensive, defensive rebound and run the floor.
"He's going to do what he's gotta do to out there to try and help his team win, and that could be misconstrued by Granger saying he's dirty, but Joakim Noah is not a guy that I ever felt coaching or being around him that he was a dirty player."