Tidenham is a village and parish in the Forest of Dean in W Gloucestershire. It adjoins the Welsh border at Monmouthshire and is E of Chepstow. The village is bounded by the river Wye to the W and the river Severn to the S.

The church stands on the side of a hill and is mostly 13th to 14thc and was heavily restored in 1857-8 by John Norton. It comprises of a S doorway with a porch and a nave with a N aisle which has four bays of continuously double-chamfered arches. There is a W tower arch but no chancel arch. There is a N organ chamber and a vestry. The lower stages of the W tower have large clasping buttresses; the SW corner contains a stair turret with an external entrance. In the mid 18thc external parts of the church were whitewashed. It is said that this was to provide a marker for shipping in the Severn estuary.

The church houses a lead font, one of six in Gloucestershire to be cast from the same mould.

The church at Tidenham has been identified with that of 'Istrat Hafren' mentioned in dubious charters of c. 700 and c. 880. The large manor of Tidenham containing 30 hides was granted by King Edwy in 956 to Wulfgar, Abbot of Bath. After 1052 Bath Abbey leased the manor for the life time of Archbishop Stigand. After the Norman Conquest it passed to William FitzOsbern in 1070 when Stigand was deposed. William FitzOsbern granted half a hide of land, the manor's church with the tithes to the Abbey of Lyre in Normandy. In 1291 the tithes of the Abbey's lands were received by Tidenham church. Tintern Abbey and Striguil received a portion of the tithes granted to Tidenham. A vicarage had been ordained by the early 13thc.