Iain is a distinctive boys' name in United States, ranking #1405 in 2005 with 106 recorded births. The name reached its all-time peak in 2003 with 126 births ranking #1181. Since 1996, the popularity has increased by 23.3%. In 2005, approximately 1 in every 18,841 boys born was named Iain. FALLING Recent data shows the name is currently falling.