[6] Barrington was a vigorous Protestant, though willing to grant Roman Catholics "every degree of toleration short of political power and establishment."

He published several volumes of sermons and tracts, and wrote the political life of his elder brother, William Barrington.

In architecture he employed James Wyatt to remodel Salisbury Cathedral, as well as the Georgian Gothic interiors of Auckland Castle, his favoured residence.

Barrington was also a primary litigant in Morice v Bishop of Durham (1805)10 Ves 522, which is a leading case on the conditions necessary to form a trust in English law.

He is buried at St John the Baptist's Church, near his home at Mongewell Park, close to Wallingford, Oxfordshire.