The chancel arch indicates that some parts of the body of the church date from the 12th and early 13th century, and the font also dates from the 12th century. However, the Romanesque remains of most significance are three carved fragments with clear links to the leading sculptor of Old Sarum in the 1130s. There is also a chevron voussoir from a large elaborate door and a volute capital, earlier in date than the other fragments.

The west tower dates from the 14th century but most of the building dates from the 19th century. The church was reworked by T. H. Wyatt in 1843 and the south arcade was replaced by E. H. Lingen Barker in 1878-79.

Domesday survey has two entries for Codford (Coteford) but it is unclear whether any or part of the lands are in what is now Codford St Mary, or whether they relate to Codford St Peter. Part of Codford was held by William de Eu, and subinfeudated to Bernard. This holding was worth £4 in 1066 and £3 in 1086. Other land in Codford was held by Osbern Giffard in 1086, when it was worth 60s. In 1066 it was held by Aelfric and valued at 50s.

The sculpture is a mixed bag, with coarse elements in the chancel arch but loose sculptural fragments of almost the highest quality. Some of the fragments bear striking similarities to the style of the leading sculptor at Old Sarum.

Fragment 2, with its beakhead has the distinctive eye form used at Old Sarum, and the character of the head is similar to a number of fragments in Salisbury Museum.

The dog’s head fragment (number 1) is obviously like similar features used as terminals to the hood moulds of the nave at Malmesbury Abbey. However, Codford probably predates Malmesbury and is therefore likely to be a reflection of nearby Old Sarum, which provides the source for so many of the forms employed at Malmesbury. No dog heads survive from Old Sarum but other features point to it having been the prototype for the form of the nave arcades at Malmesbury and, therefore, dog heads may have been present.

The detailed treatment of the dog head can be used to demonstrate more explicitly the link with Old Sarum. The bulbous oval eyes with drilled pupils were used at Old Sarum and beaded eyebrows appear on heads decorating stones from the rose window that existed at Old Sarum. The treatment of the snout is very similar to the fragment of a head from Old Sarum which was originally at the apex of the hoodmould of the nave arcade. This mask occupied the same position as a similar form at Malmesbury Abbey.

Fragment 3, the remains of a tympanum, also has clear links to Old Sarum. Incorporated into the band of geometric decoration is a roundel in which is a four pointed star with convex sides. This motif appears in a number of fragments from Old Sarum, especially those set into the wall of the cathedral close. The lion is also similar to Old Sarum, particularly to the fragment of a gable with a pair of lions. The two fragments share the elegant curling tail wrapping around the body and the long legs pointing forwards, and the line of twisted hair on the body is similar to the Old Sarum fragment’s hair running along the spine.

One of the abiding mysteries of Old Sarum is what happened to the leading sculptors following the closure of the workshop after Roger’s death in 1139. One sculptor’s hand can be recognised at Lullington (Somerset), and this influence can be traced to Lincoln and later to Malmesbury. It must be significant that Codford St Mary, in the Wylye valley, is en route to Lullington from Old Sarum.