Cornwall on Wikipedia.

Altarnun, St. Nonna. Wesleyan Chapel. Both © Bill Henderson.

Biscovey, St. Mary the Virgin. SX 058 536. The former Ebenezer Bible Christian Chapel, built in 1842, and now a sports and social club, sits in a lane opposite Biscovey Road. SX 058 535. Both © Andrew Ross.
Blisland, St. Budocus. From an old postcard in Reg Dosell's Collection - note that the card has been rather heavily processed - the original is very faded. Link.
Bodmin.
Boscastle, St. Symphorian at Forrabury. © Roger Heap. An old postcard view from Dave Westrap's Collection. 190 SX 095 909. Link1. Link2.
Breage, St. Breaca. The font. Interior view. A remarkable wall-painting. All © Carole Sarvis. Link1. Link2.
Bude.

Caerhays, St. Michael.  © Bill McKenzie. Link.
Callington, St. Mary. Link. Our Lady of Victories (R.C.). Link. Methodist Church. Link. All © Graeme Harvey (2011).
Carbis Bay, Methodist Church. SW 527 383. © Bill Henderson.
Cawsand, St. Andrew. Congregational Church. Another view. All © James Murray.
Come-to-Good, thatched Quaker Chapel. SW 813 403. © Derek Jordan. Photo is on an external web-site.
Constantine Bay, the ruins of St. Constantine's Church. From an old postcard (franked 1911), Bulman Collection. Link.
Crantock, St. Carantoc, from an old postcard in Steve Bulman's Collection. Two interior views, the Lady Chapel, and the font, both from Christopher Skottowe's Collection.
Cury, St. Corantine. © Bill McKenzie. Link.

Daymer Bay, St. Enodoc. This church has been buried beneath the sands in the past, so much so that the vicar is said to have had to enter the church via the skylight. © Charles Winpenny at http://www.cornwallcam.co.uk/. Anecdote courtesy of Rodney Hall. Another view. © Derek Jordan. Photo is on an external web-site. And a photo from Peter Wood.
Delabole, St. John the Evangelist. © Steve Bulman (2010).
Drakewalls, Cemetery Chapel. SX 425 705. © Andrew Ross.

Egloshayle - see Wadebridge.
Egloskerry, St. Keri and St. Petroc. From an old postcard in Reg Dosell's Collection.

Falmouth.
Fowey.

Gorran Haven, St. Just. From an old postcard, Geoff Watt's Collection. Link.
Gulval, St. Gudwal on Posses Lane. From an old postcard (franked 1905) in Steve Bulman's Collection. Previously in the "Unknown" section, this old family photograph shows Helen Howes' relative Isabella Gee in a churchyard. My appreciation to Greg Mishevski for the identification, who also advises that the spelling of the Saint has been at various times Gudwal, Gulval and Gulwal. Link. Grade II* listed - link. Methodist Church. © David Gallimore.
Gunnislake.
Gwennap, St. Wenappa. © Carole Sarvis. Link.
Gwinear, St. Gwinear. Another view. Both © Carole Sarvis. Link.

Hasletown, Hellesveor Methodist Church. SW 502 398. © Bill Henderson (2009).
Hayle, St. Elwyn. SW 559 375. St. Joseph (R.C.). SW 562 378. Both © Andrew Ross.
Helland, St. Helena. SX 074 710. Methodist Church. SX 073 711. Both © Bill Henderson (2009).
Helston, St. Michael. From an old postcard, Geoff Watt's Collection. Link.

Kenwyn, St. Kenwyn. From an old postcard (franked 1913 or 1918), Geoff Watt's Collection. Link.
Kilkhampton, St. James. From an old postcard, Geoff Watt's Collection. A modern view, © Graeme Harvey (2010). Link. The attractive Methodist Church. © Graeme Harvey (2010). Christian Fellowship. © Graeme Harvey (2010).

Ladock, St. Ladoca. SW 894 510. © Bill Henderson. Link.
Landewednack, St. Lanty or St. Winwallow. From an old postcard, Geoff Watt's Collection. Link.
Landrake, St. Michael. And an old postcard view, from Reg Dosell's Collection. Former Methodist Chapel (and adjoining school), now both private residences. The new Methodist Church. Interior view. All except the postcard © James Murray.
Landulph, St. Leonard and St. Dilph. From an old postcard, Bulman Collection. Link.
Lanhydrock, St. Hyderock, in the grounds of Lanhydrock House, a National Trust property. © Robin Pizzy. Two further views - 1, 2, the porch, two interior views - 1, 2, and the altar. Ancient cross in the churchyard. All © Steve Bulman (2010). Link.
Lanssalos, St. Ildierna. Link to external web-site.
Lanteglos-by-Fowey, Cornwall, St. Wyllow. Another view. Previously in the "Unknown" section, these photos were rescued from destruction by Ian Lewis, and identified by Janet Gimber. Another solved Unknown is this one from John Bowdler's Collection - identified by "Stiffleaf", who has many more photos of the church on Flickr.
Launcells, St. Swithin. Interior view. Both © Graeme Harvey (2011). Link.
Launceston, St. Mary Magdalene. From an old postcard in Steve Bulman's Collection. St. Stephen the Martyr. © Graeme Harvey (2011). Link.
Liskeard.
Little Petherick, St. Petroc Minor. SW 918 721. © Bill Henderson (2009). Link.
Looe.
Lostwithiel.

Marazion, All Saints. © Mark Summers. Another view, and the chancel, both © Gene Hawkins. Link. Society of Friends. © Rob Brettle.
Mawgan-in-Meneage, St. Mawgan. © Charles Winpenny at http://www.cornwallcam.co.uk/.
Millbrook, All Saints. Methodist Church, formerly Wesleyan, dating from 1873. Link. Cemetery Chapel. All © James Murray.
Mithian, St. Peter. SW 746 471. © Bill Henderson (2009).
Morwenstow, St. Morwenna and St. John the Baptist. SS 205 153. © Nick Hopton. Link.
Mousehole, Wesleyan Church. SW 468 261. © Andrew Ross.
Mullion, St. Mellanus. From an old postcard in Steve Bulman's Collection. Link.
Mylor Harbour, St. Mylor. Another view. Interior view. All © Carole Sarvis.

Newlyn.
Newquay.

Padstow, St. Petroc. Two interior views - 1, 2, the Prideaux Monument, two of the many angels in the roof, and the superb font. SW 915 754. Link. St. John's Methodist Church on Church Lane. SW 917 754. All © Steve Bulman (2010).
Par.
Paul, St. Pol de Leon. SW 464 271. © Andrew Ross. Another view. © Bill Henderson (2009). Link1. Link2.
Penzance.
Perranporth, the remains of St. Piran. In use until the early 19th century, encroaching sand made the church increasingly unusable, and the decision was made to dismantle the church and re-locate it further inland, at Lambourne. Much of the fabric was removed and used in the new building. Two further views - 1, 2, and an ancient cross (11th century of earlier). SW 771 565. The site of St. Piran's oratory lies nearby. SW 768 563. All © Josie Saunders (2010). Link1. Link2.
Perranuthnoe, St. Michael and St. Pirran. © Carole Sarvis. Link.
Phillack, the Parish Church. SW 565 384. © Andrew Ross.
Port Isaac, St. Peter (1884). SW 996 809. © Bill Henderson (2009). Another view, and two interior views - 1, 2, all © Steve Bulman (2010). Former Methodist Chapel (1836), now a shop. The original building seems to have been extended to the right at a later date. The relationship between the two can be better seen in this more distant view. All © Steve Bulman (2010).
Porthilly, St. Michael. © Roger Heap.
© Gerard Charmley (2011).
Poughill, St. Olaf. Link. Grade I listed - link. Methodist Church. Both © Graeme Harvey (2011).

Quethiock, St. Hugh. A large cross stands in the churchyard. SX 312 647. Both © Steve Bulman (2010).

Rame, St. Germanus. Another view. Interior view. All © James Murray.
Redruth, dedicated to St. Euny. © Charles Winpenny at http://www.cornwallcam.co.uk/.
Roche, St. Gomonda of the Rock. Of ancient foundation, but now largely of the re-building of 1822. SW 987 587. © Bill Henderson (2009).

St. Anthony-in-Meneage. © Charles Winpenny at http://www.cornwallcam.co.uk/.
St. Blazey, St. Blaize. SX 068 548. United Free Methodist Church (now flats). SX 069 546. Both © Andrew Ross.
St. Blazey Gate, Leek Seed Methodist Church at Doubletrees, built 1824, restored 1903. Another view. SX 060 537. Both © Andrew Ross.
St. Buryan, St. Buryan. SW 409 256. © Bill Henderson (2009). Link.
St. Endellion, the Collegiate Church of St. Endellion, variously St. Endelienta. Another view. SW 996 786. Both © Roger Heap. Another view © Bill Henderson (2009). Three interior views - 1, 2, 3, and carved detail on the pulpit. All © Steve Bulman (2010). Link.
St. Erney, St. Erney. © James Murray. Link.
St. Germans, St. Germanus, and the churchyard gate. SX 360 573. Both © Andrew Ross. Another view. From an old postcard (franked 1907), Steve Bulman's Collection. Link1. Link2. Methodist Church, dating from 1903. © James Murray.
St. Germoe, dedicated to St. Germoe. From an old postcard in Steve Bulman's Collection.
St. Issey, St. Issey. SW 928 718. © Bill Henderson (2009).
St. Ive, St. Ivo. Two interior views - 1, 2. The pulpit with tester, and a close-up, showing the mermaids. A carved capital, and a window. SX 305 675. All © Steve Bulman (2010). Link.
St. Ives.
St. John, St. John in Cornwall. © James Murray (2010). Another view, from an old postcard in John Bowdler's Collection. Previously in the "Unknown" section, it was identified by Simon Davies.
St. Just, St. Just. © Bill McKenzie. Former Salvation Army Hall, now a British Legion Club. © Rob Brettle.
St. Just-in-Roseland, St. Justus. From an old postcard in Steve Bulman's Collection. Link.
St. Keverne, St. Keveran. From an old postcard, Graeme Harvey's Collection. Link.
St. Kew, St. Kewa (interior view). From an old postcard in Christopher Skottowe's Collection. Link.
St. Levan, St. Levan. SW 380 222. © Bill Henderson (2009). Link.
St. Martin-by-Looe, St. Martin. © Andrew Ross.  Link1. Link2.
St. Mawgan, St. Mawgan-in-Pydar. Another view. Both © Roger Heap. And another, and an interior view. Both © Louise Kirby. An old postcard view, from Reg Dosell's Collection.
St. Merryn, dedicated to St. Merryn. SW 886 741. From an old postcard in Reg Dosell's Collection. A modern view. © Bill Henderson (2009).
St. Michael's Mount, from an old engraving in Colin Water's Collection. Link.
St. Minver, St. Menefreda. A fine building, with much of interest. The porch, sun-dial, three interior views - 1, 2, 3, and the window above the altar. The church has many fine carved bench-ends. The font, and a monument. SW 965 775. All © Steve Bulman (2010). Link.
St. Newlyn East, St. Newlina. From an old postcard in Christopher Skottowe's Collection. Link.
St. Tudy, St. Tudius. © Derek Jordan. Two views © Roger Heap. 1. 2.
Saltash, St. Stephen. Link. Wesley Methodist Church. Both © James Murray.
Sennen, St. Sennen. From an old postcard, Bulman Collection. A modern view. © Bill McKenzie. Link.
Sheviock, The Blessed Virgin Mary. Interior view. Both © James Murray. Link.
Stratton, St. Andrew. From an old postcard in Reg Dosell's Collection. A modern view, © Graeme Harvey (2010). Another view, and an interior view, both © Graeme Harvey (2011). Link.

Tintagel, St. Materiana on Church Hill. From an old postcard, Steve Bulman's Collection. A modern view. © Alex Parker. Link1. Link2.
Trebetherick, St. Enodoc. © Roger Heap.
Tregonetha, the former Tregonetha Methodist Chapel (built as Bible Christian) now seems to be a holiday let. My appreciation to Janet Gimber for the identification. SW 956 638. © Bill Henderson.
Tregrehan, Methodist Chapel. A former Primitive Methodist Chapel, now a home. Both at SX 044 537, on opposite sides of the road. Appreciative thanks to the home owner for his permission to photograph the former chapel. Both © Andrew Ross.
Trevone, St. Saviour. © Bill McKenzie. Link.
Truro.
Tywardreath, St. Andrew the Apostle. SX 085 541. Link. Methodist Church, on Church St. SX 084 542. Both © Andrew Ross.

Veryan, St. Symphorian. © Derek Jordan. Link.

Wadebridge, St. Petroc (C) at Egloshayle. Curiously, Pevsner has it as "St Conan (?)". This is perhaps because of the presence of St. Conan, a Mission Church, in Wadebridge, across the river. To add to this, the church notice board doesn't give a dedication. SX 000 719. Link1. Link2. Methodist Church at Egloshayle - for sale in 2010. Photo taken from across the river. SW 992 724. Both © Steve Bulman (2010). The Christian Centre. © Graeme Harvey (2011).
Week St. Mary, St. Mary the Virgin. SX 237 977. © Les Horn (2009). Link.
Wendron, dedicated to St. Wendron, St. Gwendron, or St. Wendrona. SW 678 311. © Steve Taylor. Link1. Link2.
Werrington, St. Martin. © Graeme Harvey (2011).

Yeolmbridge, Methodist Church. © Graeme Harvey (2011). Link.

Zennor, St. Senara. © Bill McKenzie. Link.