Cassidy is a distinctive boys' name in United States, ranking #1756 in 1997 with 55 recorded births. The name reached its all-time peak in 1996 with 78 births ranking #1371. Since 1996, the popularity has decreased by 29.5%. In 1997, approximately 1 in every 34,274 boys born was named Cassidy. STABLE Recent data shows the name is currently stable.