Cassidie is a distinctive girls' name in United States, ranking #3992 in 1999 with 29 recorded births. The name reached its all-time peak in 1998 with 31 births ranking #3745. Since 1996, the popularity has increased by 16.0%. In 1999, approximately 1 in every 61,165 girls born was named Cassidie. FALLING Recent data shows the name is currently falling.