The church comprises a W porch, nave, N and S aisles of 3 bays each, and a chancel with an organ chamber on the N side. In 1807 a tower was built on the S side of the chancel, and the N aisle was added. The S nave arcade dates from the late 12thc.

In 1086 Tillington, in the Rape of Chichester, was held by Robert from Earl Rodger. There was no mention of a church.

There is reason to believe that the W respond of the S arcade represents the beginning of the aisle campaign. The pointed arches of the three-bay N and S arcades are carried by circular piers with foliate capitals and octagonal impost blocks, and by semi-circular responds carrying, except at the W end of the S arcade, foliate capitals and five-sided impost blocks. The W bay of the S arcade is not only distinguished from the others by its W respond: the two orders of the pointed arch have broader chamfers here, and the foliage of capital 2 follows a slightly different design from all the others. Instead of continuing to the necking, the groove separating the broad, plain leaves terminates in a drilled hole half-way down the basket. In sum the arch, respond and main capital of the W bay of the S arcade represent either an experimental stage in an uninterrupted building campaign, or the beginning of a campaign which was interrupted and recommenced, after no lengthy passage of time, with slightly different architectural detailing. It can be dated to the late 12thc.

The font is thought to date from the 12th century.