The actress has been very open in the past about her love of Swift's "Shake It Off," so much so that she wrote to the singer personally to share her admiration and ask for permission to use the song in her new film, Little Monsters.
"I didn't hear from her personally, but when I heard we got the song, I knew she heard me and I was just so grateful," Nyong'o told ET on Thursday during the grand opening of the new main floor at Saks Fifth Avenue in New York City.
In the upcoming horror comedy, Nyong'o stars as Miss Caroline, a kindergarten teacher who has to protect a group of young children under her care during a zombie outbreak that threatens their lives.
In the film, Miss Caroline keeps the kids calm by playing songs on her ukulele, including Nyong'o's beloved "Shake It Off." And the actress addressed the ET cameras directly to express her gratitude.
"Taylor Swift, thank you so, so, so much," she said. "I hope you see the movie and I hope you feel that I took care of your song."
"It means everything," Nyong'o prasied. "Every milestone, everything that Black Panther has achieved so far, has been incredibly encouraging and worth celebrating."
"I'm just so proud to be a part of that film because I actually really, really love it," she added. "If I wasn't in it, I would be evangelizing about it anyway. But I'm glad I'm in it."
On Thursday, Nyong'o took center stage at the star-studded gala at Saks, where she served as the host of ICONIC, the new main floor opening event, and she couldn't have been more thrilled to be a part of the occasion.
"I'm really excited. I was really, I felt really honored when they asked me to be a part of this," Nyong'o recalled. "Saks is like a landmark for New York. It's a classic New York staple."
"I remember when I first moved to New York, coming down Fifth Avenue and seeing Saks for the first time," she added. "I just felt like I was in an episode of Sex and the City or something."
Nyong'o's Little Monsters recently debuted at the Sundance Film Festival in January, and was bought by Hulu for distribution later this year. Check out the video below for more on her work on Black Panther.