Fionna is a distinctive girls' name in United States, ranking #5440 in 2009 with 26 recorded births. This places Fionna in the top 27% of ranked US girls' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2012 with 41 births ranking #3804. Since 1996, the popularity has increased by 116.7%. In 2009, approximately 1 in every 70,649 girls born was named Fionna. FALLING Recent data shows the name is currently falling.