Millie is a highly popular girls' name in England & Wales, ranking #36 in 2025 with 1,080 recorded births. This places Millie in the top 1% of ranked UK girls' names for the year. Its actual usage is classified as Popular. The name reached its all-time peak in 2004 with 2,421 births ranking #22. Since 1996, the popularity has increased by 233.3%. In 2025, approximately 1 in every 235 girls born was named Millie. FALLING Recent data shows the name is currently falling.
Millie is a warm vintage short form that now often stands as a given name in its own right. Its exact traditional meaning depends on which longer name family sits behind it.
Its rise fits the broad return of nickname-style vintage names that feel affectionate and energetic. Millie works especially well because it is cheerful without feeling flimsy.