(1912-1998) American singer, arranger, pianist, dancer, actress, composer, author, satirist and businesswoman. Remembered now for her appearance with Fred Astaire and Cyd Charisse in Funny Face, for being the godmother of Liza Minelli, but mostly for writing Eloise: A Book for Precocious Grownups (1955) and its sequels.

A child prodigy, playing piano at the age of four, she appeared with the St. Louis Symphony at 15. Moving to California, she would appear on the radio with the Mills brothers, Fred Waring, and finally her own show. Soon she was hired by MGM as a composer, but it was her arrangements for other singers that got everyone's attention. Whether it was Frank Sinatra or Gene Kelly, Lena Horne or Judy Garland, MGM sent them to Kay for their movie songs.

In 1948, she put together a nightclub act of skits and songs at Ciro's in Hollywood, backed up by the Williams Brothers. One night, backstage, she invented a persona of a 6 year old girl, Eloise. The character was so popular, that with the help of illustrator Hilary Knight, they created the Eloise books.

The success of the books allowed her to exit show business gracefully, but nonetheless remained somewhat of a celebrity throughout the 1960s, a holdover from the glamour days of Hollywood.

In the 1980s, when Donald Trump purchased the Plaza Hotel, site of the many Eloise books, he inquired into using Eloise in advertising. Thompson refused because Trump refused to give her a free room at the hotel (as previous owners had done).