Dillan is a distinctive girls' name in United States, ranking #5144 in 2005 with 25 recorded births. This places Dillan in the top 27% of ranked US girls' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2003 with 30 births ranking #4337. In 2005, approximately 1 in every 73,908 girls born was named Dillan. FALLING Recent data shows the name is currently falling.