Millen is a distinctive boys' name in United States, ranking #13389 in 2014 with 5 recorded births. This places Millen in the bottom 5% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2000 with 9 births ranking #7213. In 2014, approximately 1 in every 384,088 boys born was named Millen. STABLE Recent data shows the name is currently stable.