Late 12th century Romanesque church; originally consisting of unaisled nave, W tower and chancel (latter now gone). Later re-working and additions, 17th century, 1822 and 1883 (R Rowand Anderson). Sited on elevated position. Rectangular-plan with aisles to S and N. Base course. Hammer-dressed, squared sandstone older masonry; stugged coursed sandstone for later additions. Ashlar margins (later work), chamfered reveals. String course; corbel table.
TOWER: 3-stage with battered base and 2 string courses. Truncated in 17th century, now with slate saddleback roof, housing dovecot; clasping buttresses to eaves line. Intermediate buttress on W front set between 2 arrowslit windows (that to right broader) and below 1st string course. Arrowslit above buttress at 2nd stage. Flight- hole access to roof with projecting cill in gablehead of W elevation. 17th century, stone bird-cage belfry on E gable of tower; piended roof and corner finials, capped by weathercock. Broad stair projection at SE corner houses newel staircase to upper floors, finishes in lean-to cap at level of upper string course; arrowslit windows. 19th century burial plot of Dudgeon family, surrounded by low wall and railings, projects from SW corner of S wall.
S ELEVATION (NAVE): blocked ornate Romanesque door at centre, stands proud of wall. Doorway recessed in 4 arch orders on free-standing jamb shafts with 'water- leaf' capitals and rectangular abaci. Semi-circular archivolt with roll and hollow moulding and deeply undercut chevron. Hoodmould with stops, chevron design visible on right hand side but weathered for remaining portion. Tripartite window off-set to left of door at clerestorey stage. Later window and door to left; bipartite rectangular window with chamfered mullion and chamfered cill; round-headed door with ashlar margin, sharply-cut chevron hoodmould. String course above window and door running to wall of tower (part of 12th centuty fabric). Small rectangular blocked opening at dado level immediately to right of door. Above to right paired-round headed windows with hoodmoulds. Corbelled coursed ashlar parapet to eaves. Nave cut away at E end by Newliston burial aisle which projects to S. Door at centre in S wall; bolection moulding. Lintel stone inscribed VIRTVTE.DECET.NON.SANGVINE NITI. ("it is better to trust in virtue, not in lineage") Date 1629, initials JD and MC inscribed. Small window at dado level to left on W return of aisle; 2 windows at upper level to left and right. 1885 memorial tablet against wall of E return of aisle; blocked opening below. Some heavy repointing on S face of aisle.
E ELEVATION: gable at centre with burial aisle to left, porch to right and E elevation of N aisle recessed to outer right. 2 rectangular, bipartite windows with semi- circular hoodmould and stops at ground. Large oculus (no tracery) at centre in gablehead. Celtic cross finial. Burial aisle to left. Lower and slightly recessed entrance porch to right, principal door on E front. Gabled door stands proud of wall. Semi-circular arch in 3 recessed orders with impost course and hoodmould. Outer orders plain, innermost roll and hollow moulding. Outer orders supported on monolithic free-standing nook-shafts, pilastered jamb; crocketed and 'waterleaf' capitals; weathered waterholding bases. Ashlar coped skew line. Tall round-headed window with hood mould on N return of porch. Recessed to right is N wing.
N ELEVATION: gable of N wing. Door at ground to left (modern). Intermediate stepped buttress terminating in below level of corbels of E and W returns. Diagonal buttress to outer right. Oculus at centre in gablehead. Bipartite window with semi-circular hoodmould to left of E return, door at lower level to right. Rectangular fanlight above ashlar lintel, long rectangular window to right. Corbelled coursed ashlar parapet above. 3, regularly placed bargeboarded, gabled timber dormers. 3-bay W return, bays grouped towards N end of wing and divided by off-set stepped buttresses; bipartite window with semi-circular hoodmould in each bay. Blank wall at right hand corner, evidence of blocked arched opening; 19th century monument built against wall. Bargeboarded dormers above bays, not glazed. Masonry of S corner evidences 17th century work, and N elevation of junction with tower shows fabric of original nave with string course, similar moulding to tower. Nave projects beyond tower. Tripartite window directly under string course at dado level. Corbelled parapet runs along entire W return and nave junction with tower.
Diamond-pane leaded glass for tower lancets, square leaded glass for main windows, stained glass windows to S elevation, plate glass for E dormers. Grey slate roof with red ridge tiles, dormers also roofed in this way. Ashlar coping to skews. Tall, square, semi-circular coped wallhead stack on E wall of burial aisle; squat coped gable stack on N gable.
INTERIOR: late 19th century; galleried on 3 sides with wooden box pews. Timber roof. Communion table at centre with wooden pulpit by David Rhind (1860). Stair to W gallery within tower. Semi-circular arch between tower and church.
WATCH-HOUSE, GATEPIERS AND WALL: circa 1820, sited on S side of gate. Single storey, 3-bay symmetrical watch- house. Squared and snecked sandstone rubble with droved margins. Raised cills. Ground slopes to S.
N ELEVATION: boarded door at centre with flanking narrow blinded windows under pedimented wallhead; square, apex stack. Gatepier built into left corner, mirrored treatment on W corner as pilaster quoins.
E ELEVATION: blind window at centre. Lower wing to left with boarded door at ground. S gatepier supporting corner and roof.
GATEPIERS: Doric piers of squared sandstone rubble with ashlar coping. Rubble wall with semi-circular coping runs from N pier around churchyard.
GRAVEYARD: number of 18th century monuments in upper churchyard, notable example to S of nave has sculpted skeletal heads with spectacles. Numerous gravestones bearing memento mori.