St Mary's is constructed in brick, rubble and carrstone, parts of which have been rendered.
 The roofs are thatched.
 Its plan is simple, consisting of a nave and a chancel with a north vestry, and a bellcote at the west end.
 The west doorway dates from the middle of the 12th century.
 Above it is a two-light window dating from 1858.
 On the west gable is a bellcote of 1871.
 In the south wall of the nave is a doorway with a plain arch, and to its east is a two-light early 14th-century window.
 The south wall of the chancel contains a two-light window, a priest's door over which is a finial, and a three-light 19th-century square-headed window.
 The east window has three lights.
On the north side of the chancel is a two-light window, and there is another two-light window in the north wall of the nave.

Inside the church are box pews dating from 1789; these were cut down in size in 1865.
 On the south wall of the nave are the remains of a wall painting depicting Saint Catherine with her wheel.
St Mary's is constructed in brick, rubble and carrstone, parts of which have been rendered.  The roofs are thatched.  Its plan is simple, consisting of a nave and a chancel with a north vestry, and a bellcote at the west end.  The west doorway dates from the middle of the 12th century.  Above it is a two-light window dating from 1858.  On the west gable is a bellcote of 1871.  In the south wall of the nave is a doorway with a plain arch, and to its east is a two-light early 14th-century window.  The south wall of the chancel contains a two-light window, a priest's door over which is a finial, and a three-light 19th-century square-headed window.  The east window has three lights. On the north side of the chancel is a two-light window, and there is another two-light window in the north wall of the nave.
Inside the church are box pews dating from 1789; these were cut down in size in 1865.  On the south wall of the nave are the remains of a wall painting depicting Saint Catherine with her wheel.
St Mary's Church, Barton Bendish