St Cewydd's church, Diserth is a single chamber church with a bold west tower, the earliest feature is the (probably) 14th century south doorway with large jamb-stones and two-centred head. The arch-braced roof could also be 14th century . The earliest window is the 16th century south chancel window. There is a three-decker pulpit and flagstone floor. Some pews are patterned with Jacobean-style diamonds and circles, and have the name, and sometimes housename, of the owner. The oldest is dated 1666.

A number of wallpaintings were discovered in 1954 including (i) on the east wall of the chancel, a stencilled diaper of roses alternationg with the mongram IHS enclosed within a border of chevrons (ii) on the north wall of the nave is a partial figure of Death (iii) on the north wall, fragments of the Ten Commandments and memento mori (fragmentary) (iv) on the south wall, fragmentary inscription in raised palster and (v) at the east end of the north wall, two palimpsest Royal Arms of the time of Queen Anne.

Sources include:
Undated notes by D.J. Roberts
Hughes, T. J. Wales's Best One Hundred Churches, 2006.
Richard Suggett, Painted Temples: Wallpaintings and Rood-screens in Welsh Churches, 1200–1800, (RCAHMW 2021), pp. 105, 106, 278.

RCAHMW 2021