Cassidi is a distinctive girls' name in United States, ranking #5928 in 2009 with 23 recorded births. The name reached its all-time peak in 1999 with 51 births ranking #2704. Since 1996, the popularity has decreased by 37.8%. In 2009, approximately 1 in every 79,864 girls born was named Cassidi. FALLING Recent data shows the name is currently falling.