St. Thomas's church is situate on the north side of ; it is a donation in the gift of the governors of , the church being originally part of the hospital, as indeed it still remains, forming a part of the south side of it, where is a door of entrance; the door for the parishioners being in . The number of inhabitants within the precinct increasing, it was made parochial by king Edward VI. and a chapel was erected within the hospital for the use of the patients. The parishioners pay no tithes or church rates, and the vestry is open. The church being old and ruinous, in it was rebuilt at the expense of granted out of the coal duty, with the further assistance of the governors and others.

The present edifice is a plain building of red brick, with stone dressings of an unassuming character. The plan is an oblong square, with a square tower attached to the south side. The tower is made in height into stories, divided by string courses. The south and east fronts have entrances enclosed in stone frontispieces, and covered with elliptical pediments resting on consoles; in the tympanum of each is a relief of cherubic heads. Over each door is a circular window; in the and stories are round-headed windows; and the elevation is finished with a cornice surmounted by an attic. At the north-west corner is an attached staircase. The west front is built against by the vestry-room, and the north abuts on the church; in such portions as are clear of these incumbrances each aspect of the elevation is alike. The south side of the church, which is seen from the street, has lofty circular arched windows, the key-stones carved with cherubim; the elevation is finished with an attic over a cornice; in the centre a pediment. The east end is entirely built against; the north side is partly built over the cloister, which surrounds the inner court of the hospital. In that portion of the wall which is clear, are windows made to correspond with the rest of the buildings: these windows are lintelled on the outside, but are arched in the interior, to correspond with those on the opposite side of the church. The ground floor of the tower forms a porch to the church: on the west side is an entrance to the vestry.

The interior of the church is exceedingly plain, and not quite uniform, owing to the intrusion of the cloister on the plan. The walls are finished with a cornice enriched with mouldings and mutules of the Doric order, upon which rests a horizontal ceiling of plain plaster without ornament. A gallery is erected over the cloister; the front, dark oak pannelled. A continuation of the same gallery covers the west end of the building. The altar- screen is composed of oak, and consists of a central and side divisions. The former has Corinthian pilasters, surmounted by their entablature and a segmental pediment; the horizontal cornice broken to let in a pannel painted with a choir of cherubs and the Hebrew name of the Deity. Between the pilasters is the decalogue. The pediment is crowned with an attic, in the centre of which is the royal arms of George I. and over them the crest; on the side pilasters the lion and unicorn; the whole executed in dark oak. The side compartments are pannels inscribed with the paternoster and creed, and covered with pediments surmounted by ill-formed obelisks ending in flames. The pulpit and desks are grouped on the south side of the altar-rails. The former is hexagonal, and rests on a pillar, but is not remarkable for ornament. The font is placed against the north wall, near the west end; it is a plain marble basin, with an oak cover. On the same side of the church, nearer the east, is a doorway, covered with an elliptical pediment, leading into the hospital. There is no organ in this church.

This church is in length feet, and in breadth feet. In the vestry-room is a picture of king Edward VI. in his robes, with this inscription;

Edwardus Sextus Dei gratia Rex Anglie et Francie, aetatis xvi.

In the front of the gallery was formerly inscribed:

This church was rebuilt and finished A. D.

1702

, sir Robert Clayton, president; deputy Thomas Eyre, treasurer.