The stage and screen icon will also sing an original song, written by composer-lyricists Marc Shaiman and Scott Wittman, with series star Christian Borle.
The announcement was made Tuesday by Robert Greenblatt, chairman of NBC Entertainment.
"Liza Minnelli is the essence of a multi-talented, singular show business sensation, particularly for her extraordinary contributions to Broadway," said Greenblatt. "So what could be more fitting than to have her legendary talent on a show that celebrates a world Liza has dazzled for decades? I had the pleasure of working with Liza when we restored her landmark television special 'Liza with a Z' at Showtime, and to see her artistry up close and personal is a thing to behold."
Minnelli's episode is titled "The Surprise Party" and will air in the spring, NBC said.