Milly is a distinctive girls' name in United States, ranking #2464 in 2009 with 78 recorded births. The name reached its all-time peak in 2014 with 129 births ranking #1657. Since 1996, the popularity has increased by 609.1%. In 2009, approximately 1 in every 23,550 girls born was named Milly. STABLE Recent data shows the name is currently stable.