Cassidy is a distinctive boys' name in United States, ranking #2481 in 2011 with 50 recorded births. The name reached its all-time peak in 1996 with 78 births ranking #1371. Since 1996, the popularity has decreased by 35.9%. In 2011, approximately 1 in every 37,980 boys born was named Cassidy. STABLE Recent data shows the name is currently stable.