Cassidy is a distinctive boys' name in United States, ranking #1770 in 1998 with 57 recorded births. The name reached its all-time peak in 1996 with 78 births ranking #1371. Since 1996, the popularity has decreased by 26.9%. In 1998, approximately 1 in every 33,532 boys born was named Cassidy. STABLE Recent data shows the name is currently stable.