Grande showed off her impression of Coolidge during a Tonight Show appearance in 2018. When Coolidge was shown the video on Thursday, she called Grande's work "unbelievable."
"It was sort of the beginning of a lot of cool things that happened for me," Coolidge said of Grande's impression. "I was sort of going through a dead zone, not much was going on. And then Ariana did this imitation on your show and you encouraged her, and then this ball got rolling."
"My friend who's like her age... she was like, 'You should DM Ariana' because I thought it was such a good imitation," she continued. "And I was like, 'No! She's got like 260 million followers. Those are robots. The robots answer the DMs.'"
Coolidge sent the DM anyway, and "this response came back, and the next thing you know I was going to her house for a wardrobe fitting for 'Thank U, Next.'"
Coolidge appeared in Grande's music video for her hit song later that year, reprising her Legally Blonde role of Paulette Bonafonté for the project.
Grande's Coolidge impression wasn't the only one that impressed the actress. She was equally blown away by Saturday Night Livestar Chloe Fineman's take on her.
"That is amazing," Coolidge praised. "It's so weird because you don't really know who you are ever, really, from an objective perspective. But then you see people [do an impression of you] and you're like, 'Oh, that's who I am? All right, I'll take it.' I liked that one."
After Coolidge appeared in the "Thank U, Next" video, she landed a role on HBO's The White Lotus, which became a hit and has since been renewed for season 2. When ET spoke with Coolidge in November, she marveled over the popularity of the series.
"It didn't matter where I was this year. It didn't matter that I had a mask on. I could be in a motorboat up in Maine going by another speedboat and someone would be like, 'White Lotus.' I mean, it was weird. Everyone saw it. Everyone saw that thing," she said. "That's the most popular thing I think I've ever done where people just came out of the woodwork. Everyone saw that show. It's so exciting."