Cassidy is a distinctive boys' name in United States, ranking #2301 in 2000 with 42 recorded births. The name reached its all-time peak in 1996 with 78 births ranking #1371. Since 1996, the popularity has decreased by 46.2%. In 2000, approximately 1 in every 46,760 boys born was named Cassidy. STABLE Recent data shows the name is currently stable.