Millie is a highly popular girls' name in England & Wales, ranking #25 in 2023 with 1,349 recorded births. The name reached its all-time peak in 2004 with 2,421 births ranking #22. Since 1996, the popularity has increased by 316.4%. In 2023, approximately 1 in every 190 girls born was named Millie. FALLING Recent data shows the name is currently falling.