What does O'Brien mean?
How popular is O'Brien?
O'Brien is a rare first name for men. O'Brien is an equivalently unique surname too for both adults and children. (2000 U.S. Census)
Below is a graphed comparison of the usage of O'Brien and corresponding names. Brain, Brian (#168 2 years ago), Brien, Bryan (#148), Bryant (#581) and Bryon are the prominent related forms of O'Brien (not ranked) ranked in the Top 1000. Other forms, like Briant, are uncommon. These relations of O'Brien were at the top of their popularity during 1970-1979 (usage of 0.5872%) and are somewhat less popular today (usage 0.3505%, ▼40.3%). Bryan has been the most popular choice, though Brian has become trendy as well over time, while Brain, Bryant and Bryon are now less common. (2014 Birth Statistics)