Cassidi is a distinctive girls' name in United States, ranking #2704 in 1999 with 51 recorded births. The name reached its all-time peak in 1999 with 51 births ranking #2704. Since 1996, the popularity has increased by 37.8%. In 1999, approximately 1 in every 34,780 girls born was named Cassidi. FALLING Recent data shows the name is currently falling.