The former parish of Whorlton St. Mary was anciently a chapelry of the parish of Gainford, then very large. It later became a perpetual curacy, the patron being the vicar of Gainford. The list of clergy goes back to 1501. The incumbents became vicars in the twentieth century.

The last resident vicar of Whorlton retired in 1970 and the benefice was placed under sequestration until it was merged with the vicarage of Barnard Castle in 1983. The parishes of Barnard Castle and Whorlton were united in 1994.

The register of baptisms begins in 1626, of marriages in 1713, and burials in 1669. 

The older volumes have been deposited in the County Records Office, but copies are available in the parish.

The ancient chapel, which had early Norman features, was demolished and replaced by a new building in 1853 at a cost of £600. It is an elegant structure, in Victorian Gothic style, soundly built of local random stone and brick.

The roof is of a high pitch, covered with green Westmoreland slate, and is supported by laminated oak trusses. A small stone tower, terminating in a pinnacle and a cross, houses two bells cast in 1715 by Samuel Smith of York.

The windows in the chancel and nave are filled with modern memorial stained glass.

The graveyard, with memorials from 1702 to the present day, is still in use.

Near the church is the parish hall, built as an independent chapel in 1840. Having fallen into disuse it was bought by the Parochial Church Council in 1958. Since 1987 it has been leased by the Whorlton Village Community Association for general community use, the church retaining the right to use it on occasions.