Iain is a distinctive boys' name in United States, ranking #7357 in 2025 with 11 recorded births. The name reached its all-time peak in 2003 with 126 births ranking #1181. Since 1996, the popularity has decreased by 87.2%. In 2025, approximately 1 in every 155,280 boys born was named Iain. FALLING Recent data shows the name is currently falling.