Caerwys Welsh Presbyterian Church, including forecourt wall and gates

The Caerwys Welsh Presbyterian Church is an early 19th-century chapel built in a simple Gothic style. The front of the chapel is constructed of snecked stone with dressed-stone voussoirs framing round-headed openings, and is topped by a slate roof with a conical ridge ventilator. It features two large windows containing small-pane, hornless sashes and tracery lights with intersecting Gothic glazing bars. The outer doorways have similar overlights and boarded doors. A central round-headed tablet between the windows records the chapel's founding and subsequent rebuilding. The side and rear walls are of rubble stone with larger quoins. Side walls each have a single window similar to the front, offset toward the rear, while the rear elevation has two similar windows.

A low, integral vestry is set back on the left side of the front, featuring a brick stack at one end and a segmental-headed, small-pane, hornless sash window in both front and rear walls. To the right of the main chapel’s front is a short link leading to a gabled school room with pebble-dashed walls and a slate roof. The link contains a vestibule and double-panelled doors. The school room's three windows have horned sashes under round heads with intersecting Gothic glazing bars; the central window is larger, and the Gothic glazing bars form an overlight. The right side wall of the school room has two horned sash windows beneath the eaves, and behind this is a lower kitchen projection with an end stack, a horned sash window, and a boarded door to its left.

A dwarf forecourt wall of rock-faced stone, topped with cast iron railings, stands in front of the chapel. It features central freestone piers with pyramidal caps and double iron gates. A rubble-stone return wall is at the left end of the forecourt, and the wall is attached to a rubble-stone boundary wall on the right.

Inside the chapel, small vestibules have panelled doors and diaper floor tiles. The main chapel has a panelled ceiling and a continuous moulded impost band. The set fawr (choir area) has panelled backing below an open balustrade, and the splayed pulpit has matching detail. Behind the pulpit is a wood-panelled reredos, and the pews have moulded ends. The school room has a single collar-beam truss.