tower added in C14.
Nave of coursed rubble, to south a C12 entrance towards west, round arch with outer shafted jambs, scallopped capitals with moulded impost blocks, roll moulded archivolt.
A C12 round headed slit window
a 2-light C14 window to centre with cusped ogee headed lights, traceried square head with a hood mould, a C19 2-light window towards east with a traceried pointed arch.
2 stage buttress to chancel which has a 2-light C14 window as on nave and, towards east, a C19 Y traceried pointed arched window, hoodmoulds.
East end has a large 3-light C14 pointed arched window, reticulated quatrefoil tracery, hoodmould, a trefoil above with moulded kneelers to coped gable parapet with ridge cross, 2 stage diagonal buttresses.
Chancel to north has a C19 window as to south and a C19 pointed arched entrance, 2 stage buttress to nave which has a C14 2-light window as to south, king
queen mask stops to hoodmould, a simple C12 chamfered round arched entrance towards west end.
Nave to north meets tower with a low buttress, quoined end reflecting height of original C12 nave.
Interior: blocked C14 tower arch, pointed with hollow chamfers stopped on mask corbels, above this on nave west wall is a small round light with a deeply splayed embrasure.
C12 light in nave to south also has a deeply splayed embrasure in a continuous roll mould broached at base, window to north has similarly roll moulded jambs.
Wall paintings in nave on north, south and west walls: scenes from life of St. Edmund, mid C13, vine scrolled borders, a cart with coffin and monks to north, Christ Enthroned with Virgin to north.
TM1072 : St Mary, Thornham Parva - Wall painting
Early C14 octagonal font to west, large base, stem moulded up to bowl which has traceried faces.
https://historicengland.org.uk/listing/the-list/list-entry/1285113?section=official-list-entry
Restored C15 screen to chancel, 2 bays of 2-lights each to each side, cusped and crocketed ogee tracery, brattished head.
Above the reredos is the Thornham Parva Retable of c.1300, probably painted for the Dominican monastery at Thetford, a triptych with 3 scenes to each panel
central Crucifixion with Virgin Mary and St. John the Evangelist flanked by SS Peter and Paul, to left SS John the Baptist, Catherine and Dominic, to right SS Edmund, Margaret and Peter Martyr, each in a cusped pointed arch, spandrels have carved roses and leaf ornament, intricate gessowork backgrounds.
In chancel in a case is a printed bible of c.1640.
Floor slab to P. Bokenham, d. 1681, and family, with arms above.
Fragments of early glass in east window and in nave to south, C19 and C20 glass in nave.