Milly is a distinctive girls' name in United States, ranking #2288 in 2011 with 82 recorded births. The name reached its all-time peak in 2014 with 129 births ranking #1657. Since 1996, the popularity has increased by 645.5%. In 2011, approximately 1 in every 21,449 girls born was named Milly. STABLE Recent data shows the name is currently stable.