St John's Church is a 13th-century church on the corner of Grainger Street and Westgate Road in Newcastle upon Tyne, England, dedicated to St John the Baptist. It is a Grade I listed building.

The old church of St. John is believed to date from c.1287. William Gray, a 16th century topographer and burgess of Newcastle-upon-Tyne, called it "a pretty little church, commended by an arch-prelate of this kingdom because it resembled much a cross".

The church, surrounded by modern buildings on three sides, is modest, with a low square tower featuring small pinnacles and windows with flattened arched tops. A stone in the south transept window commemorates Robert Rhodes, the builder of St. Nicholas' Cathedral's steeple in Newcastle, and a benefactor to the town's churches. The current stone is a copy of the original, removed around 1861 during repairs, and now housed in the castle.

The 15th-century font cover and the Jacobean pulpit are examples of local woodwork. The chancel, now the Lady Chapel, contains a window including the fragments of medieval glass with the earliest known representation of the arms of Newcastle. Further along the wall is a cruciform opening which enabled the anchorite, whose cell was above the present sacristy, to see the altar. The rood and reredos are both the work of Sir Charles Nicholson.

Part of the graveyard was built over in the 1960s for meeting rooms and a hall. As of 2010, there remained about ten gravestones. Two of these, that to Sarah and Sarah Hodgson, owners of the Newcastle Chronicle and that to the artist Ralph Waters are listed Grade II.

Irish actor and poet John Cunningham is buried in the graveyard. Not far from the east window lies a stone slab, part of a table monument, its four supporting pillars lying half buried in the soil beneath it. The inscription on it reads as follows:

Here lie the Remains of JOHN CUNNINGHAM Of his excellence As a Pastoral Poet His works will remain a monument for ages After this temporary Tribute of Esteem Is in dust forgotten. He died in Newcastle Sep. 18, 1773, Aged 44.

• St John the Baptist’s Church web site
• Photographs here