Interior
Both naves have a pitch pine wagon barrel roof of 7 bays. Each bay is articulated by a tie-beam with bar stop-chamfered soffit and brattished carving, each merlon with roll moulded cap; carried on bar stop-chamfered brackets with shaped ends. Each roof bay is subdivided into 4 tongued and grooved boarded recessed panels with moulded dividers; the naves are divided by a central arcade of 5 columns. Each column is a square timber pillar, bar stop-chamfered at the angles, and supported on a stone base. Pitch pine pews are arranged in 3 ranks, the central with divider running along the base of the arcade. The S chancel is raised by one step and has a moulded communion rail on shaped stanchions with floriate brackets; the N chancel, also raised by one step, has a moulded rail over recessed, tongued and grooved panels in chamfered surrounds.
Highly ornate carved oak pulpit. Dating from the late C17 or early C18 and comprising part of a 3-decker pulpit, originally from St. Lukes Church in Liverpool, given to the church of St. Sannan by Mr F Frodsham (Liverpool solicitor) in 1894. Square in plan and raised by steps, flanked by twisted balusters to a plain rail, leading to a doored entrance at the N side; the pulpit is of bolection moulded panels decorated with rich floriate carved borders. To the rear (W end) of the S nave is a pitch pine boarded vestry enclosure; with the upper part of open, cusped panels under a moulded rail, over tongued and grooved panelling. The church contains 2 fonts, located at the rear (W end) of the church; the earlier, disused font has a shallow marble bowl surmounted on a tall fluted limestone column with square plinth base and may date from the late C18. The font in use probably dates from the C19 restoration and comprises a wide, shaped marble bowl on a twisted column with floriate carving on the capital and bosses to the chevron design of the sloping sides at the top of the moulded drum plinth.
Glass: the S chancel window is of 3 lights, the Light of the world flanked by St Sannan and St David. By H Gustave Miller, was given by Mr Wynne Yorke of Bryn Aled in 1910, in remembrance of Pierce and Lucy Penelope Wynne Yorke of Dyffryn Aled. The N chancel window also of 3 lights, the crucifixion, flanked by the Blessed Virgin Mary and St John. The window, by Jones and Willis, was given in remembrance of the Rev John Pugh, Rector of the Parish, and Frances Jane Cooper, his wife, and is donated by their son, John Hunter Pugh. Below the window is a stone tablet to John Hunter Pugh d.1909. In the S wall, directly E of the porch, is a round-headed window dedicated to David Lees Jones, Fighter Pilot, who died in the Second World War, in 1945; the window contains a coloured light bearing the image of the face of the young man.
Memorials: N wall: marble memorial, draped medallion of a seated maiden beside an urn, and refined ornament around the tablet; to Ridgeway Owen Meyrick Esq, d.1773, son of Pierce Meyrick and descended from the Meyrick family of the Bodorgan estate on Anglesey and the Rt Hon Lady Lucy Pitt, daughter of Thomas, Earl of Londonderry. Marble memorial, by W Spence, of female figures, including 2 seated with their backs to an urn; to Pierce Wynne Yorke d.1837, and Elizabeth Yorke, his widow, d.1873, daughter of Sir W Bulkeley Hughes of Plas Coch. Marble memorial, by W Spence, of a female figure with a cross against a rocky background; to Diana Yorke d.1805, only child and heiress of Pierce Wynne and widow to Ridgeway Owen Meyrick Esq. and Philip Yorke of Erddig. N chancel: series of C19 metal coffin plates on N wall, various late C18 and early C19 slate slabs. Below E window, and in recesses, are portions of 2 stones; the first to John Roberts of Bryn Bugad and his wife Elin 1674, and to Mary wife of Foulk Salusbury 1692; the second bears the date 1682. To the right of the window is a shaped slate slab to John Foulkes, his wife Margaret and his son David who all died in October 1756; above this is a charity slate bearing the names and donations of members of the parish. S chancel: flanking the E window are painted wooden prayer tablets. S wall: marble memorial to John Lloyd of Fforest Esq. d.1753 and other members of his family. Marble memorial, by W Spence, to the family vault of Rev Brownlow Yorke d.1813 and his wife Elizabeth, d.1855.
At the W end of the church are a number of C18, and early C19 gravestones. The church also contains a warden's bench, the side panelled carved with poppy head terminals and the date 1634; and an oak warden's chest bearing the inscription: E F I W WARDEN8 1683.