Siobhan is a distinctive girls' name in United States, ranking #2668 in 2005 with 64 recorded births. The name reached its all-time peak in 1997 with 139 births ranking #1272. Since 1996, the popularity has decreased by 53.6%. In 2005, approximately 1 in every 28,870 girls born was named Siobhan. FALLING Recent data shows the name is currently falling.