Gillian is a distinctive girls' name in United States, ranking #3307 in 2025 with 47 recorded births. The name reached its all-time peak in 1999 with 1,022 births ranking #303. Since 1996, the popularity has decreased by 87.6%. In 2025, approximately 1 in every 34,197 girls born was named Gillian. STABLE Recent data shows the name is currently stable.