Milly is a distinctive girls' name in United States, ranking #3675 in 2004 with 40 recorded births. The name reached its all-time peak in 2014 with 129 births ranking #1657. Since 1996, the popularity has increased by 263.6%. In 2004, approximately 1 in every 45,903 girls born was named Milly. STABLE Recent data shows the name is currently stable.