Northumberland on Wikipedia.

Acklington, St. John the Divine. 81 NU 227 019. © Steve Bulman.
Allendale.
Alnmouth, St. John the Baptist. © David Gallimore.
Alnwick.

Bamburgh, St. Aidan, whose graveyard contains Grace Darling's grave. Both © Bill Henderson.
Belford, St. Mary. © Bill Henderson.
Berwick-upon-Tweed.
Blanchland, the Abbey of God and St. Mary the Virgin. © Bill Henderson. Link.
Blyth.
Bolton, a chapel whose mother church is Edlingham, St. John the Baptist. © Susan Sinclair.
Bothal, St. Andrew. © Sally Funk.
Branxton, St. Paul - the burial site of the fallen from the Battle of Flodden Field, 1513. © Bill Henderson.
Byrness, St. Francis. © Bill Henderson. Link.
Bywell, St. Peter. © Bill Henderson. Another view. © Peter Morgan. Link. Close by is the redundant church of St. Andrew, which is cared for by the Churches Conservation Trust. © Bill Henderson. Another view. © Peter Morgan. Link.

Chatton, Holy Cross Church (U.R.C.). 75 NU 056 282. © Steve Bulman. Link.
Chillingham, St. Peter. You shouldn't need a reason to visit the beautiful county of Northumberland, but here's one - the Grey Tomb. 75 NU 063 259. Both © Steve Bulman. Link.
Corbridge.
Cornhill-on-Tweed, St. Helen. © Bill Henderson.
Corsenside, St. Cuthbert. © Bill Henderson. Link.
Cowpen, St. Cuthbert (R.C.). © Bill Henderson.
Cramlington, St. Nicholas. © Bill Henderson.

Dilston, St. Mary's Chapel at Dilston Hall. © Bill Henderson. Link.
Doddington, St. Mary & St. Michael. © Bill Henderson.

Earsdon, St. Alban. © Bill Henderson.  Another view. © Alan Craxford. Link1. Link2. Link3.
Eglingham, St. Maurice. 81 NU 106 195. © Steve Bulman.
Elsdon, St. Cuthbert. © Bill McKenzie. Another view. © Bill Henderson.

Felton, St. Michael and All Angels. © Bill Henderson. Link. U.R.C. 81 NU 179 003. © Steve Bulman.
Ford, St. Michael & All Angels, in the grounds of the castle. Another view. Both © Bill McKenzie.

Greenhead, dedicated to St. Cuthbert. © Steve Bulman. 86 NY 660 653.

Haltwhistle, dedicated as the Church of the Holy Cross. © Steve Bulman. 86 NY 708 641. Another view, © Bill Henderson. The Two Churches, so called because it houses both the URC church and serves as St. Wilfred's RC Church. © Bill Henderson. Methodist Church. © Alan Blacklock.
Haydon Bridge.
Heavenfield, St. Oswald. © Bill Henderson. Link.
Hebron, St. Cuthbert. © Lyn Chapple.
Heddon-on-the-Wall, St. Andrew. Link. Methodist Church (formerly Wesleyan). Both © Peter Morgan.
Henshaw, dedicated as All Hallows. 86 NY 764 644. Methodist Church. 86 NY 764 646. Both © Steve Bulman.
Hepple, Christ Church. © Bill McKenzie. Link.
Hexham.
Horsley (Ovingham parish), dedication unknown. © Bill Henderson.
Horsley (in Elsdon parish), Holy Trinity.   Link. © Bill Henderson.

Kirknewton, St. Gregory the Great. © Sally Funk.
Knarsdale, St. Jude. © Martin Briscoe. Another view. © Glenn Parker.

Lambley, St. Mary and St. Patrick. Interior view. Both © Alan Blacklock.
Lesbury, St. Mary. 81 NU 236 117. © Steve Bulman.
Lindisfarne.
Long Framlington, U.R.C. © Alan Blacklock.
Longhirst, St. John. © Sally Funk.
Lowgate, St. Mary. © Alan Blacklock.
Lowick. From the description in Pevsner, I suspect this is St. John. Can you confirm? From an old postcard in Reg Dosell's Collection.

Mitford, St. Mary Magdalene. © Bill Henderson. Link.
Morpeth, St. James the Great. Link. St. Mary the Virgin. Link. U.R.C. All © Bill Henderson.

Newbiggin-by-the-Sea, St. Bartholomew. St. Mark (U.R.C.). St. Mary (R.C.). All  © Bill Henderson. Link.
Newton-by-the-Sea, St. Mary. © Martin Briscoe.
Ninebanks. © Steve Bulman. 86 NY 783 525.

Otterburn, St. John the Evangelist. © Bill McKenzie.
Ovingham, St. Mary. © Peter Morgan. Link.

Ponteland, St. Mary the Virgin. Methodist Church. Both © Bill Henderson.

Rothbury.

Seaton Delaval, Parish Church of Our Lady. From an old postcard, Bulman Collection. A modern view. © Bill Henderson. Link.
Seaton Sluice, St. Paul. © Bill Henderson.
Seghill, Methodist Church. © Bill Henderson.
Stamfordham, St. Mary. The tower. 88 NZ 076 720. Both © Steve Bulman. Link.
Stannington, St. Mary the Virgin. © Bill Henderson.
Stocksfield, Baptist Church. © Alan Blacklock.

Thropton, U.R.C. © Bill McKenzie.

Walbottle, Methodist Church. © Peter Morgan.
Warkworth, St. Lawrence. © Bill Henderson. Another view. © Steve Bulman. And another. © Alan Craxford. 81 NU 248 063. Link.
Whalton, St. Mary Magdalene. © Bill Henderson.
Whitfield, dedicated to Holy Trinity. © Steve Bulman. 86 NY 779 569. St. John. NY 778 584. © Alan Blacklock.
Widdrington, Holy Trinity. Link. U.R.C., formerly Widdrington Presbyterian Church. Built in 1893, it replaced an earlier building. NZ 253 955. Both © Alan Craxford. Another view. Interior view. Both © Lesley Taylor.
Woodhorn, St. Mary the Virgin, now in use as a museum. © Bill Henderson. Link.
Wooler, St. Mary. 75 NT 993 281. St. Ninian (R.C.). 75 NT 989 283. Both © Bill Henderson. U.R.C. 75 NT 993 279. © Steve Bulman.
Wylam, St. Oswin. © Peter Morgan. Link.