Millie is a highly popular girls' name in England & Wales, ranking #18 in 2022 with 1,670 recorded births. The name reached its all-time peak in 2004 with 2,421 births ranking #22. Since 1996, the popularity has increased by 415.4%. In 2022, approximately 1 in every 158 girls born was named Millie. FALLING Recent data shows the name is currently falling.