Gillian is a distinctive boys' name in United States, ranking #12915 in 2010 with 5 recorded births. This places Gillian in the bottom 9% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 1999 with 8 births ranking #7392. In 2010, approximately 1 in every 383,682 boys born was named Gillian. FALLING Recent data shows the name is currently falling.