Yealmpton is a parish in the South Hams area of Devon. The church sits in the middle of the town of Yealmpton on the N bank overlooking the river Yealm. Rare Kitley green marble was extracted historically nearby.

The church was rebuilt entirely in 1850 by William Butterfield in the Decorated style. The tower (unbuilt when the patron became a Catholic) was constructed in 1915 by Charles King of Plymouth. The fabric is coursed stone and ashlar, with freestone dressings, and slate roofs. The building consists of a nave and a chancel with N and S aisles, a N and S transept, a S porch and a tower.

The interior is strikingly ornamented with bands of black marble following the lines of the window arches and arcades, dark and light marble bands in the arcade piers, diaper patterns and polychromatic friezes in the chancel. John Betjeman called it ‘the most amazing Victorian church in Devon’.

A new octagonal, red and black marble font in the SW of the church was part of the Butterfield scheme. The redundant 12th-c font bowl sits (unfixed) on a table beside the eastern most column of the N aisle arcade.

Yealmpton first appears in Domesday Book in 1086 as 'Elintona', when the manor was held by the king. The Domesday Survey also contains a reference to the priests of Elintona who also hold land. In the Geld Roll, the land is held by St Mary of Yealmpton (Alentona). A church is first explicitly mentioned in a charter of 1225.

In the churchyard, now situated at the W end near to the church tower, there is an inscribed granite memorial standing stone, marked with the letters GOREUS. It consists of a granite slab 1.83 m high, 0.49 m by 0.27 m wide at its base, tapering to 0.4 m by 0.18 m wide at a point 0.3 m from the rounded top. On its E face, the inscription GOREUS in Roman capitals is inscribed vertically down the stone with the letters on their sides, roughly cut into the surface. There are 11 other similar stones in Devon. Based on the lettering, Historic England date the stone to the 6thc.