Brennin is a distinctive boys' name in United States, ranking #7260 in 2008 with 11 recorded births. This places Brennin in the top 50% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2012 with 23 births ranking #4268. In 2008, approximately 1 in every 185,450 boys born was named Brennin. FALLING Recent data shows the name is currently falling.