View the most religious surnames in Ireland

Where Does The Last Name O'Brain Come From? ^{nationality or country of origin}

O'Brain occurs in The United States more than any other country/territory. It may appear as a variant:. For other possible spellings of O'Brain click here.

How Common Is The Last Name O'Brain? ^{popularity and diffusion}

It is the 6,360,413^th most commonly occurring surname on earth, held by approximately 1 in 809,727,324 people. O'Brain occurs mostly in The Americas, where 67 percent of O'Brain are found; 56 percent are found in North America and 56 percent are found in Anglo-North America. O'Brain is also the 3,941,740^th most frequently used forename on earth, held by 9 people.

This last name is most frequently used in The United States, where it is carried by 5 people, or 1 in 72,491,787. In The United States it is most frequent in: Alabama, where 20 percent reside, Arkansas, where 20 percent reside and Colorado, where 20 percent reside. Without taking into account The United States it occurs in 6 countries. It is also common in Australia, where 22 percent reside and England, where 22 percent reside.

O'Brain Family Population Trend ^{historical fluctuation}

The frequency of O'Brain has changed through the years. In The United States the share of the population with the last name contracted 75 percent between 1880 and 2014.

O'Brain Last Name Statistics ^demography

The religious devotion of those holding the surname is principally Catholic (100%) in Ireland.