Kayin is a distinctive boys' name in United States, ranking #9319 in 2025 with 8 recorded births. The name reached its all-time peak in 2001 with 31 births ranking #2964. Since 1996, the popularity has decreased by 42.9%. In 2025, approximately 1 in every 213,510 boys born was named Kayin. FALLING Recent data shows the name is currently falling.