John Pollard Seddon (19 September 1827 - 1 February 1906) was an English architect. His father was a cabinetmaker and his brother Thomas Seddon (1821 - 1856), a landscape painter.
He was a pupil of Thomas Leverton Donaldson and C.F.A. Voysey trained under him.
Between 1852 and 1863 J.P. Seddon formed a partnership with John Prichard. Many of their major commissions were church restoration works, most famously for Llandaff Cathedral. From 1884 to 1904 he was in partnership with John Coates Carter.
His works include the University College of Wales building in Aberystwyth, St Peter's Church, Ayot St Peter, Hertfordshire and St Catherine's, Hoarwithy, Herefordshire. He was also a prolific designer of furniture, metalwork, stained glass, tiles and ceramics.