The Canadian teenager had already visited Good Morning America, Live! With Kelly and Ryan, The TODAY Show, and The View before making her late-night debut with Fallon, a former Saturday Night Live star.
Fresh off her maiden major victory over 23-time Grand Slam champion Serena Williams, Andreescu discussed the career milestone, one that has made her a superstar at home in Canada.
"I've heard from Shania Twin, President Trudeau, John Tory, Steve Nash, the Raptors and the Leafs," she said, listing the many hometown heroes who've shouted out the 19-year-old on social media.
She did, however, mention one notable exception, shouting out music artist Drake for not sending his congrats.
"Champagne Papi, I'm waiting for you," joked Andreescu, who celebrated the night of US Open victory by singing "Started from the Bottom" with her team.
The reigning BNP Paribas Open and Rogers Cup champion later demonstrated her signature racquet spin, one that briefly went haywire during her fourth round meeting with American Taylor Townsend.
"It slipped out of my hand, but no one's getting hurt tonight; I promise!"
Andreescu is scheduled to play her first match since winning in Flushing Meadows at the Dongfeng Motor Wuhan Open in two weeks.