Katy is a moderately popular girls' name in England & Wales, ranking #137 in 1999 with 344 recorded births. The name reached its all-time peak in 1996 with 413 births ranking #111. Since 1996, the popularity has decreased by 16.7%. In 1999, approximately 1 in every 819 girls born was named Katy. FALLING Recent data shows the name is currently falling.