Kay Thompson (1909-1998) was a singer, dancer, vocal arranger, and coach of many MGM musicals in the 1940s.
The Eloise character grew out of the voice of a precocious six-year-old that Miss Thompson put on to amuse her friends. Collaborating with Hilary Knight on what was an immediate bestseller, Kay Thompson became a literary sensation when Eloise was published in 1955. The book has sold more than 2 million copies to date. Kay Thompson and Hilary Knight created four more Eloise books, Eloise in Paris, Eloise at Christmas, Eloise in Moscow, and Eloise Takes a Bawth.