Dillan is a distinctive boys' name in United States, ranking #1439 in 2015 with 118 recorded births. The name reached its all-time peak in 1998 with 312 births ranking #597. Since 1996, the popularity has decreased by 50.0%. In 2015, approximately 1 in every 16,239 boys born was named Dillan. FALLING Recent data shows the name is currently falling.