See townlands.ie for lists of these enities in County Carlow;

• 7 Baronies
• 48 civil parishes
• 54 Electoral Divisions
• 602 townlands + 5 sub townlands

See the Carlow (Ceatharlach) page on logainm.ie for similar lists with slightly different totals in some categories but much else data besides.

• "The Placenames Database of Ireland was created by Fiontar & Scoil na Gaeilge in collaboration with The Placenames Branch (Department of Culture, Heritage and the Gaeltacht). This is a comprehensive management system for data, archival records and placenames research conducted by the State. It is a public resource for Irish people at home and abroad, and for all those who appreciate the rich heritage of Irish placenames."

Carlow civil parishes - on Irish Ancestors

An overview of the relationships between counties, baronies, civil parishes and townlands can be found on this page.

• The Great Britain Historical Geography Information Service (GBHGIS) provides a mass of information about Britain's localities as they have changed over time. Information comes from census reports, historical gazetteers, travellers' tales and historic maps.
• A Vision of Britain Through Time, in the GBHGIS, provides maps and statistical information derived from census reports covering the period 1801-2001, searchable by place name or post code.
• The Association of British Counties (A.B.C.) "is a society dedicated to promoting awareness of the continuing existence of the 86 traditional Counties of Britain".
• British Counties, Parishes, etc. for Genealogists (archived copy).