"You've always been so kind. That's saying a lot in this business, because we like to be mean," the Oscar-nominated "Gravity" actress said.
"There's not been one time you haven't treated me like I had something to offer. Even when the film was awful and you knew it, you never let me see it in your eyes," Bullock told Leno. "When I made crazy life decisions, you never questioned it. You were so welcoming. I just felt special, even when I was insecure."
"Well, you are special," Leno told Bullock, kissing her hand.
Jimmy Fallon will take over as emcee when the show moves to New York after the Winter Olympics.