UK and Ireland: Gazetteers

• The GENUKI Gazetteer covers the whole of England, Wales and Scotland and can be searched by place-name (or part of a place-name) or Ordnance Survey Grid Reference (six-figure, eg NZ183848). If there are multiple place-names matching the name you enter, you will initially be presented with a drop-down list of the matching place-names with their distances and bearings from London, England.
• A Gazetteer of British Place Names provided by the Association of British Counties. This comprehensive place-name index for Britain lists more than 50,000 places and gives the Ordnance Survey grid reference, the ancient or geographical County, and current local government information for each place name. There is comprehensive coverage of alternative spellings (including Welsh and Gaelic versions) and detailed notes specifically aimed at historians and genealogists. Appendices relate present day registration districts to local government areas and list those places which lay in a different "registration county" to their ancient County in the 19th century.
• The GB1900  Project - a crowd-sourced historical gazetteer based on the 1:10560 Ordnance Survey mapping of Great Britain
• GENUKI Church Database provides an online Parish Locator covering the whole of the UK. This includes facilities for listing other churches and parishes within any specified distance of the parish church.
• UK Placename Finder from Popular Archaeology includes details of 160,000 UK places.
• The archived copy of the BBC Domesday Project Reloaded website provides a method of searching the contents of the original BBC Domesday Gazetteer disk - a huge crowd-sourced description of the UK, dating from 1986 - by using the TNA Discovery Catalogue's results filtering facility.

Some historical gazetteers:

Lewis, Samuel. A Topographical Dictionary of England. 4 vols. London: S. Lewis and Co., 1831

Southall, Humphrey; Aucott, Paula; Fleet, Christopher; Pert, Tom; Stoner, Michael. GB1900: engaging the public in very large scale gazetteer construction from the Ordnance Survey “County Series” 1:10,560 mapping of Great Britain. Journal of Map & Geography Libraries, Vol. 13, No. 1, (2017), p. 7-28. [PDF]

Wilson, John M. The Imperial Gazetteer of England and Wales. Six Volumes. Edinburgh, Scotland: A. Fullerton, 1870

The National Gazetteer: A Topographical Dictionary of the British Islands. Virtue and Co., London (1868) 3 vols. [Full text - vol 1 (A-E), vol. 2 (F-M), vol. 3 (N-Z)]

Gazetteer of the British Isles. Edinburgh, Scotland: John Bartholomew and Sons, Ltd., 1966.