It is recorded in the National Heritage List for England as a designated Grade I listed building,[1] and is under the care of the Churches Conservation Trust, the Trust designated St Mary's as its first Conservation Church in 2015.

Building of the present church began in the 12th century, consisting of a nave without aisles, and a cruciform east end.

A large west tower was added, and in about the 1170s the transepts were altered to provide altars for the canons.

The church escaped any significant damage during the suppression of the college in 1548, or during the Civil War.

The top fell from the spire in 1894, causing much damage to the clerestory, and this was repaired by John Oldrid Scott.

The riddel posts and English Altar were erected during the remodeling of the sanctuary by Sir Charles Archibald Nicholson in 1931.

The Altar frontals were worked and embroidered by Beatrix Mary Pennyman, wife of the vicar, during World War I.

The octagonal font is Perpendicular, and is carved with arcading and (now headless) angels, The pulpit dates from 1853, it is polygonal, in stone, and designed by S. Pountney Smith.

[17] St Mary's bells are inscribed thus; "We were all fixed here by voluntary subscription, in the year 1775."

Glass in the north windows of the chancel and the central part of the south aisle were made for the Cistercian Altenberg Abbey between 1505 and 1532.

They depict scenes from the life of Saint Bernard of Clairvaux, and were bought for St Mary's by Rev W. G. Rowland, the vicar in 1845, at a cost of £425 (£40,000 in 2014).

Windows elsewhere consist of part of a collection of 15th-century stained glass bought in 1801 by Sir Brooke Boothby at a cost of £200 (£10,000 in 2014).

[8] These include an inscription on a plaque on the tower to the memory of Robert Cadman, a tightrope walker who was killed in 1739 when his rope broke.

Also in the tower is a recumbent effigy by Richard Westmacott junior depicting Col C. R. Cureton who was killed in India in 1848.

Inside the west entrance of the nave is a brass upon marble plaque memorial to men of the 85th Regiment of Foot who died serving in the Afghan War of 1879–80.

[20] In the north transept is a wall memorial to Rev John Brickdale Blakeway, vicar of the church, and a local historian, who died in 1826.

[23] Trinity Chapel contains separate stone tablets to men of the Shropshire Yeomanry who died in the World Wars, besides a roll of honour listing names of those who died in the Second, and a sandstone parish war memorial, headed by a crucifix, to parishioners who died during World War I, with a list of names that include VC recipient W. N.

[24][25] Katherine Harley, a Suffragist, is also commemorated on the memorial; she was killed at Monastir in 1917, while nursing Serbian refugees.

She was the sister of both Field Marshal Sir John French and the Irish Nationalist Charlotte Despard.

[26] Thomas Anderson, a soldier in the Dragoons was executed, as a deserter and Jacobite sympathizer, near the Butchers' Arbour on Kingsland, Shrewsbury on 11 December 1752.

The Revd Benjamin Wingfield, in the face of official hostility, allowed Anderson to be buried in St Mary's Churchyard and read the burial service over the grave.

[27] Dr Samuel Butler, headmaster of Shrewsbury School and later Bishop of Lichfield, is buried in the churchyard where his Latin-inscribed tombstone is still visible.

On corner posts of the stone kerbs are listed battles or campaigns from World War I in which the men died.