Gillian is a moderately popular girls' name in United States, ranking #331 in 1998 with 890 recorded births. The name reached its all-time peak in 1999 with 1,022 births ranking #303. Since 1996, the popularity has increased by 134.8%. In 1998, approximately 1 in every 1,985 girls born was named Gillian. STABLE Recent data shows the name is currently stable.