In 1139, Edwin granted the church and all its property to the then newly created Benedictine Godstow Abbey, 2 miles (3.2 km) to the northwest.

St Giles' Church is 550 yards (500 m) north of Oxford's city wall, and when built it stood in open fields.

There is a 13th- or 14th-century consecration cross consisting of interlaced circles cut into the western column of the bell tower[1] that is believed to commemorate this.

Surviving 12th-century features of the church include two windows in the north side of the clerestory of the nave and the lower parts of the bell tower.

[1] In 1542 the Crown granted St Giles' to Dr George Owen of Godstow,[1] a physician of King Henry VIII.

[1] Monuments in St Giles' church include figurines of Henry Bosworth (died 1634), his wife Alice and their three children.

[1] St Giles' church was damaged during the English Civil War,[1] in which the Parliamentarian army besieged the Royalist force defending Charles I in Oxford.

John Goad, vicar from 1644 until 1646, is said to have led services in St Giles during Parliamentary artillery bombardments of Oxford in 1645.