Lewis on Wikipedia.
 

Back, Back Free Church. There are also references to the settlement being known as Coll. Another view. NB 4825 4005. Both © Martin Richter (2013). The brief Canmore entry.
Barvas, former church, of (so far) unknown denomination, now converted to residential use. Map evidence suggests that it was built after 1897, and was closed before 1958. Older maps show it with the symbol for a church with spire, now evidently taken down. Two additional views - 1, 2. NB 366 513. All © Martin Richter (2013). Howard Richter speculates that this may have been a replacement for a demolished church which stood at NB 360 514. The Church of Scotland at NB 359 494 doesn't appear to have an on-line presence. It can also be seen here, on a 2009 Streetview.  A local informant advised that it was opened in 1909. Howard Richter also notes another current church - a Free Church at NB 353 489. Link (includes a photo).
Bhaltos, the former Mission Hall (CoS). Martin was advised by a local informant that it had been disused for "at least ten years", and is now leased to a crofter. It must pre-date 1972, when it shows on an OS map of that year. NB 088 364. © Martin Richter (2013).
Breanish, the site of the former Mission Station (CoS), now re-developed as a holiday cottage. The long, north-south aligned Mission building can be seen from above here by zooming in on the red marker on the satellite image near the bottom of the page. The church sign, and pews, can be seen here in a photo taken through a window. The Mission must post-date 1899, when it doesn't show on the OS map of that year, and was still extant for the 1972 edition. Proper dates of building and demolition not currently known. NA 993 264. Both © Martin Richter (2013).

Callanish, Free Church of Scotland. Another view. NB 218 340. Link. The former(?) Mission Hall (CoS) at NB 219 336. Current status is uncertain, but from its absence from the Church of Scotland website, and its condition, it is probably closed. All © Martin Richter (2013).
Col - see Back, above.
Cross, Free Church (1888). Another view. NB 508 622. Canmore entry. Cross Free Church (Continuing). NB 4972 6132. Their website advises that it was opened in 2003. The Church of Scotland stands at NB 5059 619. The Canmore entry advises that it was originally a United Free Church, built in 1910. All © Martin Richter (2013).

Eoropie, St. Moluag (Episcopal). NB 5195 6515. The northernmost church on Lewis, it was restored from a ruin in 1912. The building itself is of uncertain age, though old, and it stands on an ancient site. © Martin Richter (2013). Link1. Link2. Link3. Link4.

Kinloch, Church of Scotland, dating from 1911. NB 3223 3304. © Donnie Macleod (2002).

Lionel, Free Presbyterian Church. Another view. NB 5256 6367. Canmore entry. Lionel Meeting House of Cross Free Church. Old maps show that the present building had a predecessor nearby. The present church is at NB 5232 6416, parallel to the road; the earlier building stood at NB 5234 6414, at 90 degrees to the road. The maps to which I have on-line access only de-limit it's dates as having been built between 1853 and 1897; the present church between 1974 and 1992. A Church of Scotland Mission stands quite close to the meeting house, on the other side of the road, at NB 5235 6418. Another view. All © Martin Richter (2013).

Miavaig, Uig Church of Scotland. Another view. This link has some history, from wherein we learn that it was originally the Free Church (at Ceann Langabhat, or Miavaig) from 1843, Uigen Church (CoS) from 1972, and that it united with the nearby Baile na Cille Church in 1979. Baile na Cille church (1829) which is Grade B listed stood at NB 053 343. Still in use in 1998, it was subsequently closed, and was for sale in 2009 - see on Google Maps here. There is a comprehensive history (with photos) of it here. More here. NB 087 348. Both © Martin Richter (2013). Free Presbyterian Church of Scotland. NB 0870 3485. © Martin Richter (2013). Link.

North Tolsta, Free Church. NB 538 475. © Martin Richter (2013). Howard Richter advises of a former Free Presbyterian Church building, which can be seen in a 2009 Streetview here.

Shader, Church of Scotland . NB 3887 5424. Free Church. Another view. NB 3896 5434. All © Martin Richter (2013). Both churches get a (brief) mention here.
Skigersta. Howard Richter advises that Skigersta at one time had a Free Presbyterian Church, which stood at NB 5459 6182, on the south side of a minor road which runs north-east towards the coast. The site can be seen on a 2009 Streetview here. Old maps indicate that the building, which was rectangular, was aligned with its long axis parallel to the road heading off into the distance. Its far end was beyond the nearest lamp-post, and heading towards the small fence-line. A line of darker vegetation can be seen which may possibly show the line of a wall. Not marked on a map of 1911, it was in place by 1931, and was still extant on a broadly-dated map of 1974-1992.

South Dell, the former South Dell Meeting Hall (Church of Scotland). Another view. NB 488 611. A un-dated property website entry has some more photos, including the interior.  The former Ness Free Church (1844-5) stands nearby. It had a "Sold" sign in 2013. Another view. NB 4877 6113. Canmore entry. All © Martin Richter (2013).