St Mary's is a magnificent mid-14thc. church with an aisled and clerestoreyed nave of four bays, the E bay of each arcade giving onto transepts. A strainer arch of c.1400 crosses the nave a bay to the E of the chancel arch. The chancel has a N vestry, and to the S the easternmost side window has been blocked, apparently to strengthen the wall when the Dolben vault was built beneath the E end c.1710. The W tower is contemporary with the rest, although the parapet must be 15thc. It is topped by an ashlar spire with two rows of lucarnes. The spire was struck by lightning in 1897 and the top 30 feet of it rebuilt. The nave has N and S doorways, the S under a two-storey porch. The upper chamber is accessible through a turret added in 1794, and is known as the Monk's Cell. The only Romanesque work here is the font.
In 1086 Finedon was a large royal manor, previously held in dower by Queen Edith. There is no notice of the church until the 13thc., when the advowson of the rectory was in royal hands .
The font was discovered in use as a cattle trough in 1849, when it was given to the church. It now stands at the west end of the S aisle. The bowl is the only original part - it stands on 19thc. shafts. It was originally square, but the angles have been chamfered off, and each chamfer chamfered again towards the top of the bowl. The interior is approximately circular and unlined. Each face of the bowl is decorated with a sunken panel containing a figural scene in low relief, but the entire surface is so badly worn that only the forms of the figures are visible. The remains of a row of beading below the figural panel survives on the N and E faces, and some blue polychromy is visible on the E face.
E face: The best preserved of the faces shows an Annunciation under a pair of arches; the angel kneeling in profile in the left arch, facing the Virgin with her hand raised in surprise in the right. There are traces on foliage in front of the Virgin; possibly a flowering rod or a lily.
S face: All that can be said is that it appears to show a figure on a bed with a larger figure at the left end of the bed. The Nativity is likeliest in view of the other scenes, but it could be a miracle scene.
W face: A Baptism, presumably Christ's. The central figure stands in water with his hands raised, while a second figure to the right reaches a hand out towards him. Above is a cloud with a dove descending.
N face: a pair of naked figures facing one another. Their heads are entirely worn away, but the left figure has its arms raised. Assumed to be Adam and Eve, perhaps at the Fall, although there is no trace of tree or serpent.
|ext. w. at top (E-W)||0.73 m|
|ext. w. at top (N-S)||0.71 m|
|h. of bowl||0.435 m|
|int. diam. (E-W)||0.59 m|
|int. diam. (N-S)||0.61 m|