Patty Smith Hill (March 27, 1868 – May 25, 1946) was a composer and teacher who is perhaps best known for co-writing, with her sister Mildred Hill, the tune which later became popular as "Happy Birthday to You". She was an American nursery school, kindergarten teacher, and key founder of the National Association for Nursery Education (NANE) which now exists as the National Association For the Education of Young Children (NAEYC).