Dillan is a distinctive boys' name in United States, ranking #839 in 2007 with 254 recorded births. This places Dillan in the top 6% of ranked US boys' names for the year. Its actual usage is classified as Uncommon. The name reached its all-time peak in 1998 with 312 births ranking #597. In 2007, approximately 1 in every 8,170 boys born was named Dillan. FALLING Recent data shows the name is currently falling.