Millie is a distinctive girls' name in United States, ranking #2358 in 1998 with 60 recorded births. The name reached its all-time peak in 2025 with 3,353 births ranking #73. Since 1996, the popularity has increased by 76.5%. In 1998, approximately 1 in every 29,448 girls born was named Millie. RISING Recent data shows the name is currently rising.
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.