The "Busy Tonight" host previously set up a landline phone specifically for the TV mogul in the hopes that she would one day call in, and she couldn't contain her excitement when it began ringing.
"I'm gonna start crying! I can't," Busy exclaimed. "I'm not ready for this."
She was initially unsure if it really was Winfrey on the other end of the line, but quickly grew emotional when the talk show queen and actress introduced herself.
"Hello! Is this you, Busy?" Winfrey, 64, asked. "It's Oprah."
During their chat, Oprah and Busy discussed the "Selma" star's vegetable garden and harvest day, when Winfrey gathers food from her yard to cook - often documenting the process on Instagram.
Oprah also complimented Busy on her new show and shocked her further by inviting her for a visit.
"I'm so happy that you're on late night," Oprah said. "It's so good to see a woman on late night!"
"I adore you! Have a wonderful holiday, Oprah," the 39-year-old responded. "And, you know, give the dogs and Stedman (Graham, boyfriend) a kiss for me."