Eris O'Brien CMG (20 September 1895 – 28 Feb 1974) was an Australian prelate of the Catholic Church and historian.
The family moved to Sydney and Eris studied at St Aloysius' College.
The same year he was a member of the Australian delegation to the third session of the United Nations General Assembly in Paris and sat on the committee dealing with human rights.
O'Brien was made Archbishop of Canberra-Goulburn in 1953 and dealt with rapid expansion of church parishes and schools in Canberra.
He died in Richmond, New South Wales in 1974, and was interred in St Christopher's Cathedral, Canberra.