Cassidy is a distinctive boys' name in United States, ranking #2713 in 2005 with 40 recorded births. The name reached its all-time peak in 1996 with 78 births ranking #1371. Since 1996, the popularity has decreased by 48.7%. In 2005, approximately 1 in every 49,929 boys born was named Cassidy. STABLE Recent data shows the name is currently stable.