Argyll and Bute on Wikipedia.

The following islands have their own sub-page - Iona, Islay, Mull.

A'Chleit, the Killean & Kilchenzie parish church. © Martin Briscoe.
Achahoish, the South Knapdale Parish Church. © Martin Briscoe.
Appin, the ruins of the old parish church. © Martin Briscoe. The Parish Church. NM 938 459. © Martin Briscoe. Another view, © Bill Henderson (2013).
Ardbrecknish, St. James. © Martin Briscoe.
Ardchattan, the parish church which dates from 1836, and replaced an earlier church of 1731/2 near Ardchattan Priory. The priory was a Valliscaulian foundation dating from 1230, which was later converted to secular use before being replaced by the church. Both © Argyll Extracts. Another view of the parish church. © Peter Amsden.
Ardlui. © Martin Briscoe.
Ardpeaton. © Martin Briscoe.
Ardrishaig, the parish church. A chapel. Both © Martin Briscoe.
Arinagour (on Coll), the former Free Church. For sale in 2011. Parish Church. Both © Tim Flitcroft (2011).
Arrochar, the parish church. The remains of the previous parish church sit immediately adjacent. Both © Martin Briscoe.
Ascog (Bute), Church of Scotland. © Bill McKenzie.

Ballymenoch, the ruins of the chapel. © Martin Briscoe.
Balvicar (on Seil Island), Free Church. A photo of a photo, taken (with permission) by Alan Blacklock at a small museum on Seil Island.
Barcaldine, a church converted to residential use. © Martin Briscoe.
Barrapol (on Tiree), Parish Church (CoS, 1902). © Tim Flitcroft (2015). Link1. Link2.
Bellanoch. Another view. Both © Martin Briscoe. And another © Peter Amsden.
Benderloch, St. Modan. NM 905 383. Link. Campbell Memorial Hall, possible converted church?. Both © Martin Briscoe. James Napier has been in touch to advise that the Memorial Hall pictured is the original building, sold in 1980, and that it has been replaced by a "Marley" structure build adjacent. He says the building in the photo has a "Free Kirk" look about it, but he isn't certain if it was a church. Les Horn has advised that this was built as a Memorial Hall to John Campbell (1823-1897), postmaster, botanist, and Bard of Clan Campbell, so never a church.

Bridge of Orchy, Strathfillan Parish Church. © Martin Briscoe.

Campbeltown.
Cardross, the Parish Church. NS 344 776. The remains of the Old Parish Church (just the tower remains, following bomb damage in WWII). NS 349 773. Both © Martin Briscoe.
Carse, the Kilberry Parish Church. © Martin Briscoe.
Clachan, Lismore Island, St. Moluag (Parish Church and former Cathedral). © Rob Brettle. Link.
Clachan, the former Free Church of Scotland. Thanks to Norman Campbell for advising the denomination. Kilcalmonell parish church. Both © Martin Briscoe.
Claonaig, disused church. © Martin Briscoe.
Colintravie. © Bill McKenzie.
Connel, disused church. Another disused church, or perhaps village hall. St. Oran at NM 914 342. . All © Martin Briscoe. Another view, © Bill Henderson (2013).
Cowal, the Kilfinan Parish Church. © N. Argyll Extracts.
Craignish parish church. © Martin Briscoe.
Craigrownie (nr. Kilcreggan), the Parish Church. The Church Hall, formerly the United Pentecostal Church. Both © Martin Briscoe.
Creich (near Fionnphort), St. Ernan (CoS). © Bill McKenzie. Another view. © Peter Amsden (2009).
Cullipool (on Luing), St. Peter (Episcopalian). A photo of a photo, taken (with permission) by Alan Blacklock at a small museum on Seil Island.
Cumlodden. © Martin Briscoe.

Dalavich, the Kilchrenan & Dalavich Parish Church. © Martin Briscoe.
Dalmally, Glenorchy Church. It's dated here to 1808, on the site of earlier churches. NN 1676 2752. © Martin Briscoe. Another view, © N. Argyll Extracts. The parish was formerly known as Clachan Dysart. The current church, the third on this site, was built in 1810. Text in italics © Argyll Extracts. Two interior views - 1, 2, and a close-up of a window, all © Chris Stafford (2013). A Free Church is shown on the 25" O.S. map of 1899, at NN 1694 2728. It pre-dates a map of 1874, and had been demolished no later than 1954. A house now stands on the site, seen here by Streetview in 2011. What may be its successor stands abandoned to the west of the village, at NN 1662 2736. Seen by Streetview in 2022, it's identified as a free church here.
Drumlemble, Presbyterian Mission Hall. © Martin Briscoe.
Dunagoil (on Bute), St. Blane's Chapel. © Bill McKenzie.
Dunbeg.
Dunoon, St. John (CoS, originally Free Church, 1877) on Hanover Street and St. Andrew Street. Another view. NS 1722 7693. Link. High Kirk (aka Dunoon Old and St. Cuthbert's). Built in 1816-17 on the site of an earlier church. Another view. NS 1742 7655. All © Chris Stafford (2013). Free Church of Scotland on Argyll Street. © Magnus Park. Link.

Ford. © Martin Briscoe.

Garelochhead, the Parish Church. Our Lady of the Sea (R.C.). Both © Martin Briscoe.
Gigha, the Gigha and Cara Parish Church at Ardminish. © Les Horn. Another view © Martin Briscoe. The ruins of St. Cathan's Church, and the Kilchattan Burial Ground. © Martin Briscoe.
Glenbarr. This building looks like a church - can you confirm it? Janet Gimber has advised that at one time it was Glenbarr Mission Hall. © Martin Briscoe.
Glendaruel, the Kilmodan Parish Church. © Bill McKenzie.
Grogport (former church). NR 809 443. © Bill McKenzie.
Gruline, (Mull), St. Columba (Episcopal). © Martin Briscoe.

Helensburgh.

Inveraray.
Inverchaolain, CoS. NS 090 753. © Ann Galliard. Link.
Inverkip. © Martin Briscoe.
Iona.
Islay.

Kames, the Kyles Parish Church. Free Presbyterian Church. Both © Martin Briscoe.
Kilbrandon (on Seil Island), the scant remains of the medieval chapel. The present church (CoS) was built in 1866. Both are photos of a photo, taken (with permission) by Alan Blacklock at a small museum on Seil Island. Another view of the present church. © Peter Amsden. Link.
Kilbride, the Chapel. © Martin Briscoe.
Kilbride, the ruins of Old Kilbride Kirk. NM 857 257. © Martin Briscoe.
Kilchrenan, the church. © Martin Briscoe.
Kilkivan, ruined chapel. © Martin Briscoe.
Killevin, the burial ground, with the possible remains of the church built into the mausoleum. © Martin Briscoe.
Kilmartin. © Bill McKenzie. Two interior views - 1, 2, both © Kevin Price (2012).
Kilmelford, the parish church. © Martin Briscoe. Another view. © Les Horn.
Kilmeny. © Martin Briscoe.
Kilmichael, Kilmichael Glassary Church. © Martin Briscoe.
Kilmichael of Inverlussa. © Martin Briscoe.
Kilmore, the ruins of St. Bean, in use until 1876. © Martin Briscoe. Kilmore Kirk (Kilmore and Oban CoS). NM 871 258. © Martin Briscoe. Another view, © Bill Henderson (2013). Link.
Kilmorich, Church of Scotland. © Bill McKenzie.
Kilmory, Kilmory Knap ruined chapel, dedicated to St. Maelrubha. Another view. NR 702 751. Both © Martin Briscoe. Another view, and an information board, which gives a little history, both © John W. Smith. Link.
Kilmun. © Les Horn.
Kilninver, the Parish Church. © Martin Briscoe.
Kirkton, the ruins of Kirkton Chapel, on the Craignish Peninsula. Interior view. Ancient tombstones (from circa 800 A.D.). All © Peter Amsden. Link.

Lochawe, St. Conan's Kirk. Another view , and two interior views, 1, 2. NN 115 267. All © Alan Blacklock. Another view, © Bill Henderson (2013), and an old postcard, from Jim Parker's Collection. Another interior view, this one from an old postcard in Paul E. Barnett's Collection. The cloister, another three of the interior - 1, 2, 3, the rose window, organ, and the figure of Robert the Bruce, with, below it, a fragment of bone from his tomb at Dunfermline Abbey, all © Dennis Harper (2019). Link.
Lochgair. © Martin Briscoe.
Lochgilphead.
Lochgoilhead. © Bill McKenzie.
Luss. © Bill McKenzie.

Machrihanish, the Pans Mission Hall (now a private residence). Dated above the door "1889". © Martin Briscoe.
Minard, the Lochfyneside Free Church. Lochfyneside parish church. Both © Martin Briscoe.
Muasdale, ruined church (just south of A'Chleit). © Martin Briscoe.

Oban.

Pennygown, the Old Chapel. NM 604 433. © Martin Briscoe.
Poltalloch, St. Columba. © Martin Briscoe.
Portnacroish, Holy Cross Episcopal Church, consecrated 1815. NM 926 473. © N. Argyll Extracts. Another view, © Bill Henderson (2013). Grade B listed.
Portsonachan, the church. © Martin Briscoe.

Rosneath, St. Modan. St. Gilda (R.C.). Both © Martin Briscoe.
Rothesay, Bute, the Chapel at Mount Stuart House. From an old postcard in Paul E. Barnett's Collection.

Sadell, the Sadell and Carradale Church. The ruins of Sadell Abbey. Both © Martin Briscoe.
Sandbank (near Dunoon). © Ann Galliard.
Scalasaig (on Colonsay), CoS, and now also used by the Baptists. © Peter Amsden.
Scarinish (on Tiree), Baptist Church. © Tim Flitcroft (2017). Link.
Skipness.
Southend, the Parish Church. Free Church. Both © Martin Briscoe.
Strachur and Strathlachlan. The Parish Church. Free Church. Strathlachlan Old Church. All © Martin Briscoe.

Tarbert, NR 863 686. Free Church of Scotland. Both © Martin Briscoe.
Tarbet, former Church of Scotland. © Bill McKenzie.
Taynuilt (R.C.). The former Muckairn Free Church. Both © Martin Briscoe. Muckairn Parish Church. © Argyll Extracts. A Telford church built in 1829 adjacent to the ancient Killespickerill Church built ca. 1500, which was itself built on the site of a 13th century church. Text in italics © Argyll Extracts.
Tayvallich. Ruin in Carsaig burial ground, described by Martin as a possible old chapel. Both © Martin Briscoe. A few miles south-west of Tayvallich stands the ruined Keills chapel, now re-roofed to protect some ancient and medieval grave-slabs; an information board gives some history. NR 691 805. Both © John W. Smith. Link.
Tighnabruaich, the former Free Church (1863), now a private residence. © Bill McKenzie. Two additional views- 1, 2, both © Chris Stafford (2012).
Torosay, the Torosay and Kinlochspelve church. © Martin Briscoe.