Plastered walls and N arcade of four pointed arches on chamfered square piers. N aisle has pointed barrel vault. C19 rafter roof to nave, with arch braces to make 11 bays. Ashlar S transept and chancel arches, both double-chamfered with no capitals. S transept C19 rafter roof. N aisle third window in blocked pointed opening of a lost transept. E end of N aisle has deep chamfered pointed tower arch. Tower has vaulted ground floor with thick square ribs (similar to those at Monkton Old Hall) to octagonal vault with octagonal centre opening.
Chancel has C19 pointed boarded ceiling with transverse ribs. Quarter-round stone corbel table on S wall and N wall to right of tower. N wall left has lower corbels carrying wall-thickening for tower, over pointed triple-chamfered low tower arch. Blocked rood loft door to left of tower arch, and blocked external N door to right. S wall has small pointed piscina and deep recess above. C13 arched S door with two continuous roll-moulds and a hood (like the door at Monkton Priory). Damaged, possibly C13, niche over with C17 tablet to Andros Anderson Marcer, from Switzerland, died 1622. Stone curved vault and stone benches. Porch extension with roof of 1937. W wall plaque 1937, and plaque of 1822 with 'James Hird/ Rich Ormond/ Church/ wardens/ WB Fech'. E wall pointed door to space between church and Clock House.
Fittings: C12 square font, scalloped, with darts, sloped in to rope moulding at top of round shaft. Large reredos of 1893 by Pearson, Bath stone, carved by N. Hitch. Christ with Evangelist symbols and angels to big canopied centre panel, musician angels each side, in two banks of two, with canopies copied from C15 canopies on Adams memorial (see below). Stone side panelling with ogee crocketted heads. Altar of 1940, with marble shelf and low oak back of c. 1920. Pulpit, 1880, by Pearson with blind tracery and angle crocketted piers. Ornate stalls by K. McAlpin 1909, the ends carved with lily and rose, front with ringed shafts, leaf cusps and lilies and roses. Pitch pine pews by Pearson. Inner W porch 1992 by P.M. Bartosch. S transept has Gothic oak reredos and altar of 1946 and dado panelling. N aisle has altar and reredos of c. 1932, and matching door to tower. Timber Gothic altar rails, 1937. Organ by Conacher 1890 in Gothic case. Chancel tiles 1884, carpeted over. In sanctuary, carved chair with panel of St Peter, perhaps reused continental work.
Stained glass: Two W windows 1879, four Evangelists, by Clayton & Bell. E window 1907 by Kempe & Co, Crucifixion and four saints. By Kempe & Co: chancel S right 1918 and centre c. 1918; nave S left 1916 and right 1910; and 3 N aisle windows 1909. Patterned glass in chancel S, c. 1879. S transept S, 1908.
Monuments: Adjoining chancel arch, fragments of a late medieval relief in alabaster, converted in 1607 to a monument to the Adams family of Paterchurch, itself dismantled. In front is a damaged Bath stone pedestal with stepped top to Roger Adames, died 1707. On wall to left, slate neo-Grec plaque to W. H. Adams, died 1833, and stone to Robert Seafort died 1630. Chancel N memorial to Edward Byam of Antigua died 1768, wreathed oval. Fine Bath stone plaque to R. and J. Meyricke, children, died 1606, small, flanked by half figures with Ionic capitals, under large cartouche; C17 plaque above to W. Goodacre, with cartouche, cherub heads, and winged skull. Chancel S, Brig-Gen Sir F. Meyrick, died 1932, with carved arms, designed by Herbert Allen, artist of Tenby; 2nd Lt W George, killed 1918, oval alabaster with wreath. N aisle N plaque to John Gwyther, died 1737, with winged cherubs and skull; marble plaque to Lt Col S. Ferrior, killed at Waterloo 1815, by Reeves of Bath. N aisle E, memorial to Lt Gen Alexander Adams, died 1834, neo-Grec with banner, by R. Westmacott Jr; plaque to Charlotte Adams, died 1814, with torches, by Harris of Dublin. In S transept, fine memorial to Francis Parry, Mayor, died 1688, brass in painted stone frame with broken pediment, cherubs and hourglass. Nave S: brass to W. Hulm JP died 1886, by Mayer & Co; later C20 oval plaque to R D R Davies; granite plaque to Lt R. Treweeks RN, killed 1915; War Memorial plaque in alabaster frame.