The show is slated to air on the network Nov. 26, live from New York's Little Shubert Theatre. O'Donnell is to join Minnelli in a "fun song and dance number to a tune that Minnelli hasn't performed in 30 years," NBC said.
Minnelli, the daughter of entertainer Judy Garland and film director Vincente Minnelli, will join previously announced guest stars including recording artists Ne-Yo and Alanis Morissette, comedian Kathy Griffin and actress Jane Krakowski for the special.
Minnelli won an Oscar for her work in the movie "Cabaret," an Emmy for her 1973 TV special "Liza with a 'Z'" and a Tony for her performance in the Broadway show "Flora the Red Menace." Her other film credits include "New York, New York" and "Arthur."