Fionna is a distinctive girls' name in United States, ranking #5677 in 2010 with 24 recorded births. The name reached its all-time peak in 2012 with 41 births ranking #3804. Since 1996, the popularity has increased by 100.0%. In 2010, approximately 1 in every 74,055 girls born was named Fionna. FALLING Recent data shows the name is currently falling.