Dillan is a distinctive boys' name in United States, ranking #608 in 1999 with 300 recorded births. The name reached its all-time peak in 1998 with 312 births ranking #597. Since 1996, the popularity has increased by 27.1%. In 1999, approximately 1 in every 6,400 boys born was named Dillan. FALLING Recent data shows the name is currently falling.