Obrien is a distinctive boys' name in United States, ranking #9328 in 2006 with 8 recorded births. This places Obrien in the bottom 34% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2005 with 11 births ranking #6983. In 2006, approximately 1 in every 256,890 boys born was named Obrien. FALLING Recent data shows the name is currently falling.