Milly is a moderately popular girls' name in England & Wales, ranking #312 in 1998 with 115 recorded births. The name reached its all-time peak in 2004 with 460 births ranking #116. Since 1996, the popularity has increased by 134.7%. In 1998, approximately 1 in every 2,515 girls born was named Milly. FALLING Recent data shows the name is currently falling.