Fianna is a distinctive girls' name in United States, ranking #9939 in 2012 with 11 recorded births. This places Fianna in the bottom 49% 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 2012, approximately 1 in every 160,067 girls born was named Fianna. STABLE Recent data shows the name is currently stable.