John Prichard (6 May 1817 – 13 October 1886) was a Welsh architect in the neo-Gothic style. As diocesan architect of Llandaff, he was involved in the building or restoration of many churches in south Wales.
John Prichard was born in Llangan, Glamorgan, on 6 May 1817, the twelfth son of the rector Richard Prichard, who served as vicar-choral of Llandaff for 35 years. He was descended from the Prichard family of Collenna. John Prichard trained as an architect under Thomas Larkins Walker, and as a result was deeply influenced by the ideas of Augustus Pugin; much of his work was in a neo-Gothic style.
He established a practice in Llandaff, Cardiff, becoming the official diocesan architect in 1847. Between 1852 and 1863 he was in partnership with John Pollard Seddon. Many of his major commissions were restoration works, most famously for Llandaff Cathedral (1843–69); Prichard and Seddon worked on the cathedral from the 1840s until 1869, when the south-western tower was completed (to Prichard's own design). Much of their work was destroyed by enemy bombing during the Second World War.
Prichard died, unmarried and childless, at the age of 69, and is buried on the south side of the cathedral. On Prichard's death, Seddon succeeded him as diocesan architect.
The Prichard Bridge, named after the architect, was built in about 1880 to allow carriages to cross the feeder channel between the River Taff and the Llandaff corn mill. It is a Grade II listed building. The mill was demolished in about 1932 and the stream no longer exists; the lower part of the bridge is buried and no longer visible.