Bullock, 49, is on the promotion trail for her new movie "Gravity."
During her chat with Ross, she revealed she learned The Sugarhill Gang song to impress a boy when she was in school, and can still remember the words.
"I learned the words because I liked this guy in high school, and I was like, 'Next time I go to that dance, I'm going to know every word, and I'll make sure he sees me lip-syncing it, and I'm going to catch his eye, and I'm gonna say the words, and he's going to like me,'" Bullock recalled. "And sadly, it worked."
She said she and co-star George Clooney sang the song to amuse themselves on the set of "Gravity," then she gave the audience a little preview of her rapping ability.
The clip has been viewed more than 40,000 times since it was posted on YouTube Sunday.