Siobhan is a distinctive girls' name in United States, ranking #1646 in 2000 with 108 recorded births. The name reached its all-time peak in 1997 with 139 births ranking #1272. Since 1996, the popularity has decreased by 21.7%. In 2000, approximately 1 in every 16,815 girls born was named Siobhan. FALLING Recent data shows the name is currently falling.