Milly is a distinctive girls' name in United States, ranking #3109 in 2003 with 48 recorded births. The name reached its all-time peak in 2014 with 129 births ranking #1657. Since 1996, the popularity has increased by 336.4%. In 2003, approximately 1 in every 38,064 girls born was named Milly. STABLE Recent data shows the name is currently stable.