The Oscar winner, who stepped away from the public eye in the weeks after her husband Jesse James' infidelity was exposed in the press, was brought onstage by Johansson and her former co-stars Betty White (The Proposal) and Bradley Cooper (All About Steve) to accept the MTV Generation Award.
The honour is given to movie stars who have provided entertainment to young audiences over the last two decades.
Bullock, who received a standing ovation, told the crowd: "Sit down, we're on a time limit, people. It's live, we're on live television."
She then thanked presenters White and Cooper, joking: "I'd like to thank Bradley for still being my friend given the only film he's been in that bombed was the one that I made. I'd like to thank Betty for being such an extraordinary woman. I love her more every day and it's not just for her extraordinary work but for the person she is and the life she lives and I want your life."
Bullock proceeded to make light of rumours she's planning to quit acting by quipping, "So the Generation Award - is that an award for old people that have extended their welcome so we should make nice and leave so someone new can come in? Because that's not going to happen, I'm staying. Because no matter what you may have seen or heard or read lately I love what I do and I'm not going anywhere."
She then shared an awkward moment with Johansson, who confessed Bullock was her favourite to take home the Best Kiss trophy, which was won by Kristen Stewart and Robert Pattinson earlier in the evening.
A blushing Bullock gushed, "It was a really nice kiss and that's nice of you to (say)," prompting Johansson to step forward and plant a kiss on her lips, sending the crowd into an uproar.
But the actress was quick to silence the audience, making reference to her personal life: "Now that we have done that, can we please go back to normal? Because therapy is really expensive."
Bullock's MTV Movie Award appearance came just one day after she showed up at the Guys Choice Awards in Los Angeles, where she picked up the Troops Choice Award for Entertainer of The Year, voted for by members of the military.
Bullock is the first female to pick up the MTV Generation Award honour.