The 31-year-old singer will perform her Grammy-nominated song "Praying", which she also co-wrote amid her legal battle with producer Dr Luke, whom she has accused of rape and abuse.
"When I wrote 'Praying', with Ben Abraham and Ryan Lewis, I just felt as if I had gotten a huge weight off of my shoulders," Kesha wrote on Twitter.
She also shared a picture of Madison Square Garden in New York City, where the annual music gala will be held.
"It felt like an emotional raw victory for myself, one step closer to healing. I never could have known what would've happened these past few years," the singer added.
"I just want to say that I needed this song in a very real way. I'm so proud and nervous and overwhelmed to be performing it at the Grammys on Sunday, and if you need it, I hope this song finds you," she wrote.
Kesha is nominated in the Best Pop Vocal Album category for 'Rainbow'.