Iain is a distinctive boys' name in United States, ranking #2261 in 2014 with 59 recorded births. This places Iain in the top 16% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2003 with 126 births ranking #1181. Since 1996, the popularity has decreased by 31.4%. In 2014, approximately 1 in every 32,550 boys born was named Iain. FALLING Recent data shows the name is currently falling.