Gillian is a moderately popular girls' name in United States, ranking #303 in 1999 with 1,022 recorded births. The name reached its all-time peak in 1999 with 1,022 births ranking #303. Since 1996, the popularity has increased by 169.7%. In 1999, approximately 1 in every 1,736 girls born was named Gillian. STABLE Recent data shows the name is currently stable.