Siobhan is a distinctive girls' name in United States, ranking #1442 in 1998 with 119 recorded births. The name reached its all-time peak in 1997 with 139 births ranking #1272. Since 1996, the popularity has decreased by 13.8%. In 1998, approximately 1 in every 14,848 girls born was named Siobhan. FALLING Recent data shows the name is currently falling.