View the most religious surnames in Ireland

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

The last name O'Brain occurs more in The United States more than any other country or territory. It may also be rendered in the variant forms:. Click here to see other potential spellings of this last name.

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

The surname is the 6,360,413^th most frequently occurring family name in the world, borne by around 1 in 809,727,324 people. This last name is mostly found 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. It is also the 3,941,740^th most widely held first name globally. It is borne by 9 people.

The last name is most frequently occurring in The United States, where it is held by 5 people, or 1 in 72,491,787. In The United States O'Brain is most common in: Alabama, where 20 percent are found, Arkansas, where 20 percent are found and Colorado, where 20 percent are found. Excluding The United States O'Brain occurs in 6 countries. It is also found in Australia, where 22 percent are found and England, where 22 percent are found.

O'Brain Family Population Trend ^{historical fluctuation}

The frequency of O'Brain has changed through the years. In The United States the number of people bearing the O'Brain surname declined 75 percent between 1880 and 2014.

O'Brain Last Name Statistics ^demography

The religious adherence of those bearing the last name is principally Catholic (100%) in Ireland.