The 33-year-old singer donned metallic body paint and a silver ensemble for her tribute to T. Rex, its frontman Marc Bolan, and music producer Hal Willner during Tuesday's episode of the late-night show.
On Instagram, Kesha said the performance, which was filmed remotely, is one of her favorite performances of all time.
"one of my most fave artists of all time and one of my favorite songs.... one of my fave performances ever!!!!!" she wrote.
Kesha later said it was an "honor" to perform the tribute.
"I LOVE T REX THIS IS SUCH AN HONOR," she wrote.
Kesha's cover of "Children of the Revolution" appears on the T. Rex tribute album Angelheaded Hipster: The Songs of Marc Bolan & T. Rex, released in April. The album also features covers from Nick Cave, Father John Misty, U2 and other artists.
Bolan died in a car crash at age 29 in September 1977. Kesha's performance aired the evening before the 37th anniversary of Bolan's death. Willner died of complications from COVID-19 in April.
Kesha released her fourth studio album, High Road, in January. She has since released the single "Since I Was Young" with Wrabel.