St Wulfram's is a Grade I listed building. A few stones of the original Saxon Church remain near the organ loft and remains of the Norman church can be seen in the Nave. The Norman Church was hit by lighting in 1222 and destroyed by fire. Other than the two west bays the North aisle arcades date from 1180. Many 13th Century Masons' marks can be seen in the west of the church as well as near the spiral stairs leading to the belfry. In 1450 the North Aisle was extended and in 1496 St Katherine's chapel was added. In 1550 the South Aisle was lengthened and the Lady Chapel built.
Sir George Gilbert Scott undertook restoration work to St Wulfram's in 1866/7.
There is a chained library - probably the first public library - housed in a room over the south porch. In the West front of the tower can be seen 12 medieval niches or tabernacles which contain modern statues of various saints Mary & Dr John Hine a former bishop of Grantham.