Fianna is a distinctive girls' name in United States, ranking #18428 in 2008 with 5 recorded births. This places Fianna in the bottom 10% of ranked US girls' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2015 with 24 births ranking #5534. In 2008, approximately 1 in every 378,144 girls born was named Fianna. STABLE Recent data shows the name is currently stable.