Llan () and its variants (; ; ; Irish and ) are a common element of Celtic placenames in the British Isles and Brittany, especially of Welsh toponymy. In Welsh the (often mutated) name of a local saint or a geomorphological description follows the Llan morpheme to form a single word: for example Llanfair is the parish or settlement around the church of (Welsh for "Mary"). Goidelic toponyms end in -lann.
The various forms of the word are distantly cognate with English land and lawn and presumably initially denoted a specially cleared and enclosed area of land.Oxford English Dictionary, 1st ed. "land, n.¹". Oxford University Press (Oxford), 1901.Oxford English Dictionary, 1st ed. "laund, n." Oxford University Press (Oxford), 1902. In late antiquity it came to be applied particularly to the sanctified land occupied by communities of Christian converts. It is part of the name of more than 630 locations in Wales and nearly all have some connection with a local patron saint. These were usually the founding saints of the parish.Baring-Gould, Sabine. The Lives of the Saints, Vol. 16, "The Celtic Church and its Saints", p. 67. Longmans, Green, & Co. (New York), 1898. The founder of a new llan was obliged to reside at the site and to eat only once a day, each time taking a bit of bread and an egg and drinking only water and milk. This lasted for forty days, Sundays excepted, after which the land was considered sanctified for ever. The typical llan employed or erected a circular or oval embankment with a protective stockade, surrounded by wooden or stone huts.Baring-Gould, p. 33. Unlike Saxon practice, these establishments were not chapels for the local lords but almost separate tribes, initially some distance away from the secular community.Baring-Gould, p. 92. Over time, however, it became common for prosperous communities to become either monasteries forbidden to lay residents or fully secular communities controlled by the local lord.Baring-Gould, pp. 37–38.
In the later Middle Ages llan also came to denote entire parishes, both as an ecclesiastical region and as a subdivision of a commote or hundred.
Place names in Wales
Places named after saints () Llanaelhaearn, Saint Aelhaiarn Llanafan Fawr 'Great Llanafan', Saint Afan Llanafan Fechan 'Little Llanafan' (now often 'Llanfechan'), Saint Afan Llanafan y Trawsgoed (alternatively, Llanafan, Ceredigion), Saint Afan Llanallgo, Saint Gallgo see St Gallgo's Church Llanarmon, Gwynedd, Saint Garmon Llanarmon Dyffryn Ceiriog, Saint Garmon Llanarmon Mynydd Mawr, Saint Garmon Llanarmon-yn-Iâl, Denbighshire, Saint Garmon or St. Germanus of Auxerre Llanarthney, St Arthney Llanasa, Saint Asaph Llanbabo, Saint Pabo Llanbadarn Fawr, Ceredigion, Saint Padarn Llanbadarn Fawr, Powys St Padarn Llanbadarn Fynydd, Saint Padarn Llanbadarn y Garreg, Saint Padarn Llanbadoc, Saint Madoc see St Madoc's Church, Llanbadoc Llanbadrig, Saint Patrick Llanbedr or Llanbeder, Newport St Peter Llanbedr, Saint Peter Llanbedr, Crickhowell St Peter Llanbedr (Radnorshire), Saint Peter Llanbedr Dyffryn Clwyd, Saint Peter Llanbedrgoch, Saint Peter Llanbedrog, Saint Petroc Llanbedr-y-cennin, Saint Peter Llanbedr Pont Steffan, St Peter Llanbeulan, Saint Peulan Llanberis, Saint Peris Llanblethian, Saint Bleiddian Llanbrynmair, Saint Mary Llandanwg, Saint Tanwg Llandecwyn, Saint Tecwyn Llandefaelog Fach, Powys, St Maelog Llandegveth, St Tegvedd Llanddeiniol, St Deiniol Llanddeiniolen, Saint Deiniol Llandderfel, Saint Derfel Llanddeusant, Anglesey, two saints: Saint Marcellus and Saint Marcellina Llanddeusant, Carmarthenshire, two saints: Saint David and Saint Teilo Llanddew, St David Llanddewi Nant Honddu (Llanthony), St David Llandegfan Saint Tegfan Llandegla, Saint Tegla Llandegley, Saint Tegla Llandeilo, Saint Teilo Llandeilo'r-Fan Saint Teilo Llanddaniel Fab Saint Deiniol Fab see St Deiniol's Church, Llanddaniel Fab Llanddewi, St David Llanddewi Brefi, Saint David Llanddewi'r Cwm, St David Llanddewi Rhydderch, St David Llanddewi Velfrey, St David Llanddewi Ystradenni, St David Llanddoged, Saint Doged Llanddona, Saint Dona see St Dona's Church, Llanddona Llanddwywe, Saint Dwywe Llanddyfnan, Saint Dyfnan Llandetty, Saint Detyw and Saint Tetta Llandissilio, Saint Tysilio Llandogo, in Welsh Llaneuddogwy, St Euddogwy (Oudoceus) Llandough, Llanfair, Saint Dochau/Dochdwy Llandough, Penarth, Saint Dochau/Dochdwy Llandrillo, Denbighshire, Saint Trillo Llandrillo yn Rhos, Saint Trillo Llandrinio, Saint Trunio Llandudoch, Saint Dogmael Llandudno, Saint Tudno Llandwrog, Saint Twrog Llandybie, Saint Tybie Llandyfaelog, St Maelog Llandyfan, St Dyfan Llandyfriog, Saint Brioc Llandyfrydog, Saint Tyfrydog see St Tyfrydog's Church, Llandyfrydog Llandygai, Saint Tegai Llandyrnog, Saint Tyrnog Llandysilio, Saint Tysilio Llandyssil, Saint Tysul Llandysul, Saint Tysul Llanelieu, St Ellyw see St Ellyw's Church, Llanelieu Llanelltyd, Saint Illtud Llanenddwyn, Saint Enddwyn Llanfachreth, Saint Machreth, (derived from the Welsh soft mutation of that saint's name, and not to be confused with Llanfachraeth which is from , 'small', and , 'beach' Llanfaelog, Saint Maelog Llanfaelrhys, Saint Maelrhys Llanfaethlu, Saint Maethlu see St Maethlu's Church, Llanfaethlu Llanfairfechan `Little Saint Marys Parish` Llanfaglan, Saint Baglan Llanfallteg, Llanfallteg West, St Mallteg Llanfechell, Saint Mechell Llanfflewyn Saint Fflewin See St Fflewin's Church, Llanfflewin Llanfigael, Saint Figael see St Figael's Church, Llanfigael Llanfoist, St Ffwyst Llanfwrog, Anglesey Saint Mwrog Llanfwrog, Denbighshire Saint Mwrog Llanedi, Saint Edith Llanedeyrn, Saint Edeyrn Llanedwen, St. Edwen see St Edwen's Church, Llanedwen Llanengan Einion Frenin, also known as Engan Llannefydd, Saint Nefydd Llanegryn, Saint Egryn Llanegwad, Saint Egwad Llaneilian, Saint Eilian Llanelian-yn-rhos, a former civil parish in Conwy County Borough, Saint Elian (Wales) Llanelidan, Saint Elidan see St Elidan's Church, Llanelidan Llanellen, Saint Elen, often anglicised as St Helen Llanelli, Saint Elli Llanelly, St Elli Llanelwedd, Saint Elwedd Llanelwy, Saint Asaph Llanenddwyn, Saint Enddwyn Llanerfyl, Saint Erfyl Llaneuddog, Saint Euddog Llanfair, Gwynedd, St Mary Llanfair Caereinion, St Mary Llanfair Clydogau, St Mary Llanfair Dyffryn Clwyd, Saint Mary Llanfair-Nant-Gwyn St Mary Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch, Saint Mary and Saint Tysilio Llanfair Talhaiarn St Mary, Saint Alhaiarn(?) Llanfair-yng-Nghornwy Saint Mary Llanfechan or Llanafan Fechan, Saint Afan Llanferres, Saint Berres (Brice of Tours) see St Berres' Church, Llanferres Llanfihangel-ar-Arth, Saint Michael, the Archangel Llanvihangel Crucorney, St Michael, the Archangel Llanfihangel Glyn Myfyr, the Archangel, Michael (Mihangel) Llanfihangel Rhydithon, St Michael, the Archangel Llanfihangel Nant Brân, St Michael, the Archangel Llanfihangel Nant Melan, St Michael, the Archangel Llanfihangel Rogiet, see St Michael and All Angels Church, Llanfihangel Rogiet Llanfihangel-uwch-Gwili, St Michael, the Archangel Llanfihangel Talyllyn, St Michael (Mihangel) and All Angels Llanfihangel y Creuddyn, St Michael (archangel) Llanfihangel-yng-Ngwynfa, St Michael, the Archangel Llanfihangel-y-Pennant, St Michael, the Archangel Llanfihangel-y-Pennant, Dolbenmaen, St Michael, the Archangel Llanfihangel Ysgeifiog, St Michael and All Angels Llanfihangel-y-Traethau, Saint Michael, the Archangel Llanfihangel yn Nhowyn, St Michael, (Mihangel) the Archangel Llanfilo, Saint Bilo Llanfoist, Saint Fwyst Llanfrothen, Saint Brothen see St Brothen's Church, Llanfrothen Llanfrynach Saint Brynach Llanfyllin, Saint Myllin Llanfynydd, Mountain Church Llanfyrnach, Saint Brynach Llangadfan, Saint Cadfan Llangadog, Saint Cadoc Llangadwaladr, Saint Cadwaladr Llangadwaladr, Powys, Saint Cadwaladr Llangaffo, Saint Caffo see St Caffo's Church, Llangaffo Llangain, Saint Cain Llangammarch Wells, St Cadmarch Llangain, St Cain Llangan, St Canna Llanganten, St Cannen Llangasty Tal-y-Llyn St Gastyn Llangathen, Saint Cathen Llangattock-Vibon-Avel, St Cadoc (Cattwg) Llangattock Lingoed, St Cadoc Llangattock (Crickhowell), St Cadoc Llangedwyn Saint Cedwyn see St Cedwyn's Church, Llangedwyn Llangeinor, St Ceinwyr Llangeinwen, Saint Ceinwen Llangeitho, Saint Ceitho Llangeler, Saint Celer Llangelynnin, Saint Celynin Llangelynnin, Gwynedd, Saint Celynin Llangennech, Saint Cennych Llangennith, Saint Cenydd Llangenny St.Cenau or Saint Keyne Llangian, Saint Cian Llangiwg near Pontardawe, St Ciwg Llangloffan, Saint Cloffan (fictitious) Llanglydwen, St Clydwen Llangollen, Saint Collen Llangolman, Colmán of Dromore Llangovan, Saint Govan Llangrannog, Saint Carannog Llanrhian, Saint Rhian Llangristiolus Saint Cristiolus Llangunllo, Saint Cynllo Llangunnor, Saint Ceinwr Llangurig, Saint Curig Llangwyfan, Aberffraw Saint Cwyfan see St Cwyfan's Church, Llangwyfan Llangwyfan, Denbighshire, Denbighshire, Saint Cwyfan Llangwyfan, Aberffraw, Saint Cwyfan Llangwnnadl, Saint Gwynhoedl Llangwyryfon, Saint Ursula Llangwyllog Saint Cwyllog Llangybi (Llangybi, Monmouthshire, Llangybi, Gwynedd and Llangybi, Ceredigion) Saint Cybi (or Cuby) Llangyfelach, Saint Cyfelach Llangyndeyrn, Saint Cyndeyrn Llangynfelyn, Saint Cynfelyn Llangynhafal, Saint Cynhafal Llangynidr, St Cynidr Llangynin, Saint Cynin Llangynog, Saint Cynog Llangynog, Carmarthenshire St Cynog Llangynwyd, Saint Cynwyd Llangystennin, Mochdre, Conwy St. Cystennin (Constantine) Llangywer, Saint Cywair Llanharan, Saint Aaron Llanhennock, Saint Henwg Llanhilleth, From Welsh `Llanheledd` 'Church of Saint Heledd` Llanidan, St. Nidan Llanidloes, Saint Idloes , Saint Iestyn Llaniestyn, Gwynedd, Saint Iestyn Llanigon, Saint Eigon Llanilar, Saint Ilar Llanilid, St Ilid Llanishen (Llanisien), Saint Isan Llanishen, Monmouthshire, St Isan Llanismel, anglicised as 'St Ishmaels', Pembrokeshire, Saint Ismael (Saint Isfael) Llanismel, anglicised as 'St Ishmael', Carmarthenshire, Saint Ismael Llanllawddog, Saint Llawddog Llanllechid, Saint Llechid Llanllibio, Saint Llibio Llanllowell, Saint Llywel Llanllwchaiarn, Saint Llwchaiarn see St Llwchaiarn's Church, Llanllwchaiarn Llanllwchaiarn, Ceredigion Llanllwni, St Llwni Llanmadoc, Saint Madoc Llanmartin, Saint Martin Llanmihangel, Vale of Glamorgan, St Michael, the Archangel Llannefydd, Conwy County Borough Saint Nefydd Llannon, Saint Non Llanon, Saint Non Llanwnnog, Saint Gwynog Llanpumsaint, five saints: Gwyn, Gwynno, Gwynoro, Ceithio and Celynin Llanrhian, Saint Rhian Llanrhidian, St Rhidian Llanrhychwyn, Saint Rhychwyn Llanrhyddlad, Saint Rhyddlad Llanrhystud, St Rhystyd Llanrwst, Saint Grwst Llansadurnen, St Sadurnen Llansadwrn, Anglesey, Saint Sadwrn see St Sadwrn's Church, Llansadwrn Llansadwrn St Sadwrn Llansamlet, Saint Samlet Llansanffraid Glan Conwy Brigid of Kildare (Saint Ffraid) Llansannan, Saint Sannan Llansannor, St Senwyr Llansantffraed, (Talybont-on Usk) St Ffraid Llansantffraid, Ceredigion, St Ffraed Llansanffraid Cwmdauddwr St Fraid Llansantffraid Glyn Ceiriog, St Fraid Llansantffraed-in-Elwell, St Ffraed Llansantffraed, Monmouthshire, St Brigid (Ffraid/Bride/Bhrid) Llansantffraid-ym-Mechain, Saint Ffraid Llansawel, Saint Sawell Llansilin, Saint Silin Llanspyddid, St Ysbyddyd Llanstadwell, St Tudwal Llansteffan, Saint Stephen Llanstephan, Powys, St Stephen (or Ystyffan) Llanstinan, St Justinian Llantilio Crossenny St Teilo Llantilio Pertholey St Teilo Llantood, The name of the hamlet is assumed to derive from the 5th century saint, Illtyd Llantrisant, three saints: Illtud, Gwynno and Dyfodwg Llantrisant, Anglesey, three saints: Afran, (possibly a variant of Afan) Ieuan, and Sana Llantrisant, Monmouthshire, three saints: St Peter, St Paul and St John Llantrithyd, of St Illtyd Llantwit Major (), Saint Illtud Llantwit Fardre ('Llanilltud on the Prince's own farm'; from : [on the] 'land (or farm) of the prince'), Saint Illtud Llantysilio, Saint Tysilio Llanvaches, Saint Maches