Io is a distinctive girls' name in United States, ranking #9311 in 2012 with 12 recorded births. This places Io in the top 48% of ranked US girls' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2022 with 18 births ranking #6548. In 2012, approximately 1 in every 146,729 girls born was named Io. FALLING Recent data shows the name is currently falling.