Cassy is a distinctive girls' name in United States, ranking #11446 in 2010 with 9 recorded births. The name reached its all-time peak in 1998 with 50 births ranking #2700. Since 1996, the popularity has decreased by 78.0%. In 2010, approximately 1 in every 197,481 girls born was named Cassy. FALLING Recent data shows the name is currently falling.