Caitlyn is a moderately popular girls' name in United States, ranking #124 in 1999 with 2,673 recorded births. The name reached its all-time peak in 1998 with 2,937 births ranking #115. Since 1996, the popularity has increased by 14.5%. In 1999, approximately 1 in every 664 girls born was named Caitlyn. FALLING Recent data shows the name is currently falling.