Casidy is a distinctive girls' name in United States, ranking #5289 in 2002 with 22 recorded births. The name reached its all-time peak in 2001 with 26 births ranking #4588. Since 1996, the popularity has increased by 37.5%. In 2002, approximately 1 in every 81,674 girls born was named Casidy. FALLING Recent data shows the name is currently falling.