Gothic hall church of different periods, consisting of tower and spire at W dated 1690, plain rectangular chancel dated 1794 incorporating 15th century W wall, chancel and gallery stair Alexander Hutcheson, 1899. Rubble built, harl pointed at S elevation of chancel, stugged and snecked with ashlar dressings at 1899 additions, irregular quoins to earlier parts, slate roof. 2-stage tower with spire. Large pointed windows with timber Y-tracery at S elevation, rectangular windows to N with round-headed cross-shaped astragals and cathedral glass at gallery level, stepped pointed windows to chancel, Tudor-arched doors and windows to stair tower and chancel porches, round windows and square- headed louvred belfry openings to tower; wallhead course, leaded coped skews with skew blocks, cross-finial to E gable.
W GABLE: tower advanced to centre, slightly advanced 1st stage with door, tall 2nd stage with 3 round windows (date plaque to lowermost), round window to return elevations, belfry opening and 2 round blocked openings to top at N, S and W elevations, balustraded parapet, further set-back stage with slated broached spire and lucarnes, clock face to E and W, weathercock finial; 2-stage stair tower recessed at right re-entrant, rounded angle, door and window to 1st stage, 3 windows to 2nd stage, curved roof; single storey rounded heating chamber to left re-entrant, door, curbed roof; evidence of earlier smaller gable within current gable recessed to left and right.
S ELEVATION: 5 windows, centre blocked, sundial to left angle.
E GABLE: datestone at gable apex, chancel gable advanced to centre with tripartite window, pentice-roofed porch at left and right re-entrants each with door (window to left return).
N ELEVATION: 3 windows to ground floor, 3 windows at gallery level above.
INTERIOR: boarded dado, panelled gallery at W end, pitchpine pews with plain poppyhead finials; pierless round-headed chancel arch with carved memorial panels to members of the Paterson of Castle Huntly family, Robert Lorimer 1900; 2 manual and pedal organ, John Compton Ltd, London W4, 1924; octagonal pulpit with carved panels of unknown date or origin depicting various Biblical and allegorical scenes; various stained glass windows, including chancel window in memory of William (d1889) and Anne Brand (d1885) of Mylnefield, by Robert Burns, Edinburgh; memorial plaques on N wall, Forrester family of Millhill, Lyon of Ogil (late 18th century), John Gelychtly grave slab (15th century); Mylnefield pew contains fragments of pre-Reformation font, bell presented by Earl Patrick, memorial stone to Appollonia wife of David Lyon of Castle Lyon dated 1698; 2 grave slabs on N wall of tower (circa 13th century), grave slab on S wall, Andro Smyth, dated 1643.
CHURCHYARD, GATEPIERS AND OUTBUILDINGS: rubble churchyard wall to N, S, E and W, round-and rubble-coped, ashlar gatepiers at N; tombstones of 16th-20th centuries, including cast-iron Wilkie tombstone (1865), large Gothic Low of Mylnefield tombstone at E wall, Paterson of Castle Huntly tombstones at S wall, (Robert Lorimer). Rectangular-plan, rubble piend-roofed building (possibly hearse house) at NW angle with large paired doors to Main Street; small square-plan rubble building at SE angle of original churchyard, pyramidal stone slate roof, door and window; lychgate at original S wall leading to churchyard extension, stepped walls and quadrant.