Cassidy is a moderately popular girls' name in United States, ranking #410 in 2020 with 765 recorded births. The name reached its all-time peak in 1999 with 3,395 births ranking #99. Since 1996, the popularity has decreased by 73.1%. In 2020, approximately 1 in every 2,112 girls born was named Cassidy. STABLE Recent data shows the name is currently stable.