The vast majority of placenames in Ireland are anglicisations of Irish language names; that is, adaptations of the Irish names to English phonology and spelling. However, some names come directly from the English language, and a handful come from Old Norse and Scots. The study of placenames in Ireland unveils features of the country's history and geography and the development of the Irish language. The name of Ireland itself comes from the Irish name Éire, added to the Germanic word land. In mythology, Éire was an Irish goddess of the land and of sovereignty (see Ériu).

In some cases, the official English or anglicised name is wholly different from the official Irish language name. An example is Dublin: its name is derived from the Irish (meaning "black pool"), but its Irish name is (meaning "town of the hurdled ford").

Etymology

Names of Irish Gaelic origin For most of the Gaelic period, there were very few towns or large settlements in Ireland. Hence, most places were named after noteworthy features of the landscape, such as hills, rocks, valleys, lakes, islands, and harbours. As time went on, more places were named after man-made features, such as churches, castles, and bridges. Some of the most common elements found in Irish placenames are shown in the table below. The differences in spelling are often due to differences in pronunciation.

Anglicised spelling Irish English translation Example(s)agha, aghy, aghey, aughafieldAghalee, Aughagowerardhigh, height, hillArdcroney, Ardfert, Ardglassard, at, athfordArdsallis, Attymass, Athlone, Athenry, Athybal, balli, bally, belhomestead, settlementBalbriggan, Ballinagree, Ballycastle, Ballyjamesduff, Ballymoney, Ballymena, Belcarraballi, ballina, bally, bella, bellana, ballaghnaford-mouth (see béal and áth)Ballinhassig, Ballinasloe, Ballybay, Bellagowan, Bellavary, Bellanagare, Ballaghnatrillickbally, balla(gh), bella(gh)pass, passageBallybofey, Ballyclare, Ballaghaderreen, Ballaghmorebane, bain, baunwhiteStrabane, Kinbain, CregganbaunbegsmallBunbeg, Carrickbegbel, bellmouth, rivermouthBelclare, Belgooly, Belmullet, Belfast, Belturbetben, binpeakBenbaun, Binevenaghboher, barroad, path, boreenBoherbue, Bohernabreena, Bohernagloghborrisborough, burgageBorris, Borrisokane, Borrisoleighboy, bueyellowBawnboy, Curraghboy, Boherbuebrackmottled, speckledBallybrack, Mullaghbrackbunriver bottom, foot, mouthBunbeg, Buncrana, Bundorancashelstone ringfortCashel, Cashelorecappa(gh)plot, tillageCappagh, Cappamore, CappawhitecarncairnCarndonagh, Carnmoneycarrow, carry, carhoo, cahernaquarterCarrowdore, Carrowteige, Carryduffcarrig, carrick, craigrock, rocky outcropCarrigaline, Carrick, Carrickfergus, Carrickmacross, Craigarogancahir, caherstone ringfortCahir, Cahircon, Caherdanielclareplateau, (of) level landClarecastle, Claremorris, Belclare, Cooraclareclo(gh), cloughrockClonakilty, Clogheen, Clogher, Cloughjordanclon, clone, cloonmeadowClondalkin, Clonmel, CloondaracoomhollowCoomkeencorsmall round hillCornafulla, Corblonogcorry, currycorrieRockcorry, Tubbercurrycrogh, croaghstack, pileCroghan, CroaghgormcrosscrossCrossbarry, Crossmaglen, Crossmolinacul, coolback, behindCultra, Coolafancy, Coolderrycul, cool, colenook, cornerCuldaff, Coleraine, Coolrain, Cloonacoolder, derry, dor, doregrove, oak-groveDerry, Edenderry, Glandore, Kildorrery, Ballaghaderreendona(gh)churchDonaghadee, Donabate, Carndonaghdroghed, drohed, drohidbridgeDrogheda, Carrigadrohid, Clondrohiddrom, drum, drimback, ridgeDromod, Dromore, Drumcondra, Drumshanbo, Drimoleaguedub, duff, duvblackDublin, Claddaghduff, Cloughduvdun, doon, down, downestronghold, fortDunboyne, Dungannon, Dungarvan, Doonbeg, Downpatrick, Lansdowneennis, inch, innis, innish, inishislandEnnis, Enniscorthy, Enniskillen, Inch, Inniskeen, Inishcroneesk, eisheskerEskrafermenFermanagh, Fermoyfin, finn, venclear, white, fairFinglas, Ballyfin, Ventryfreagh, frackheatherLetterfrackgarv, gorvroughGarvagh, Garvaghey, Gorvaghgee, gweeestuaryGeesala, Gweedoreglas, glassstreamGlasnevin, Douglas, Finglasglen, glanvalleyGlencullen, Glenties, Glenveagh, Glanmire, GlanworthgormblueGalgorm, Ben GormgortfieldGort, Gorteen, Gortnahoeillan, illaun, islandislandIllanmaster, Islandeadyinver, ineer, ennerriver mouth, estuaryInver, Rossinver, Dromineerkil, killchurchyard or graveyardKill, Kildare, Kilkenny, Killiney, Kilrushkil, killwoodlandKilbehenny, Kilcogy, Killycollie, Kilmacthomaskin, ken, con, can, carnheadKinallen, Kinlough, Kinsale, Kenmare, ConavallaknockhillKnockbridge, Knockcloghrim, KnocklyonleagreyKillylealetterhillsideLetterfrack, Letterkenny, Lettermorelis, lissearthen ringfortLiscannor, Lismore, Lisnaskea, Listowel, Lisselton, LissycaseyloughlakeLoughgall, Loughrea, Loughshinnylurganlong ridgeLurgan, Ballynalurganmaum, maammountain passMaum, Maammagh, may, moy, moi(gh)plainMagherafelt, Maynooth, Mayo, Moycullenmona, moneymoor, turf, peatlandCornamona, Ballymoneymona, money, winga, winna, winny, vinna, vinny, vunnia, bonni, bunnythicketMoneygall, Carrowmoney, Kilmoney, Ballywinna, Ballinvinny, Bonniconlonmonasterabbey, monasteryMonasteraden, Monasterevinmorebig, greatBallymore, Baltimore, Kilmore, Oranmore, Tullamoremulla(gh), mulhsummitMullagh, Mullaghmore, Mullaghbawn, MulhuddartmullinmillMullinahone, Mullinavat, Mullingar, BellanamullianoenewBallynoe, TemplenoeowenriverOwenbegpoll, poulholePollagh, Poulaphouca, Poulpeastyportstronghold, fortPortlaoiseportport, harbour, landing placePortadown, Portmarnockrath, rahearthen ringfortRathdrum, Rathfarnham, Rathmines, Raheen, Rahenyrea(gh), reva(gh)brindled, speckledLoughrea, Moneyreagh, CloonsheerevaghroeredCarraroe, Murroe, Portroeros, ross, rosh, rus, rushwood, wooded promontoryRoscommon, Roscrea, Rush, Kilrush, New Ross, Carrickmacross sall, salla, sallywillow(s)Ballysally, SallinsshanoldShanballymore, Shandon, Shankillsheskinmarsh, quagmireSheskinske, skey, skay, skea(gh)(thorn) bush, hawthornSkehana, Skeheenarinky, Ballyskeagh, Clonskeaghskreen, skrine, skryneshrineSkreen, SkryneslievemountainSlievenamon, Slieve Donardsra(gh), srah, stra, strad, strath, strawfloodplainSragh, Stranorlar, Stradone, Strathfoyle, Strawta(gh), taugh, te, tee, ti(gh)houseTaney, Taghadoe, Taghmaconnell, Taughboyne, Templeogue, Timoleague, TydavnettemplechurchTemplemore, Templenoe, Ballintempleter, tir, tyrterritoryTerenure, Terryglass, Tirconaill, Tyronetermonrefuge, sanctuaryTermon, TermonfeckintievehillsideTievebulliaghtober, tubberwater wellBallintober, Tobermore, Tubberclare, Tubbercurrytra, trybeach, strandTragumna, Tralee, Tramore, Ventrytuam, tom, toomburial moundTuam, Tuamgraney, Toomevaratulla(gh), tully, tullowhillock, mound, heapTullamore, Tullyallen, Tullyhogue, Tullowturlough, turlaghturloughTurlough, Turloughmore, Turlaghmoreorlar, urlar, urlaurfloor, flat landStranorlar, Urlarvea(gh), vei(gh)(of) birchBallyveagh, Glenveagh

Names of Norse origin During the 800s and 900s, Vikings from Scandinavia raided monasteries along Ireland's coasts and waterways. The Vikings spoke the Old Norse language and are also called Norsemen. They set up small coastal camps called longphorts – these were used as bases for their raiding parties and as shelters during the winter. Eventually, some longphorts grew into Norse settlements and trading ports. The biggest of these were Dublin (which became a Norse-Gaelic kingdom), Wexford, Waterford, Cork and Limerick. Over time, the Norsemen embraced Gaelic language and culture, becoming known as the Norse-Gaels (Gall-Ghaeil in Modern Irish, Gall-Gaidhel in Old Irish).

Placenames derived from Old Norse: EnglishOld Norse(approximation)Old NorsetranslatedIrish(modern)NotesArklowArkells-lágArkell's low place an tInbhear MórThe Irish was historically anglicised as Invermore.Blasket Braskersharp reefBlascaod Unclear origin, first recorded as Brascher, Braschet, Brasquei.CarlingfordKerling-fjǫrðrold woman fjordCairlinnCopeland IslandsKaupmanneyjarmerchants' islandOileáin Chóplainn The Norse name appears in Hákonar saga Hákonarsonar (1230). Later influenced by the Norman surname de Coupland, Copeland.Dalkey——DeilginisThe name is a meld of deilg (Irish) + ey (Norse).DurseyÞjórrs-eybull islandBaoi Bhéarra or Oileán Baoi FastnetHvasstǫnn-eysharp-tooth islandCarraig Aonair—FotaFódr-øyFoot islandFóiteUncertain etymology, possible means "foot" as it is at the mouth of the River Lee.HaulbowlineÁl-bolingeel dwellingInis Sionnach—Helvick Hellavik, Helgavík bright bay, healthy bay, safe bay, holy bayHeilbhicThe Irish is a Gaelicisation of the Old Norse. Hellvik, Norway probably has the same root.HowthHǫfuðheadBinn Éadair—Ireland's EyeIreland's øyIreland's islandInis Mac Neasáin Originally called Eria's Island; this was later confused and it became "Erin's Island"; the Norse word øy ("island") was added, and this was later confused with English "eye."Keyser's Lanekeisa?bendCúlán Chaosair Street name found in Drogheda, Dublin, Waterford, Wexford and Cork. Believed to derive from Old Norse, perhaps keisa ("bend") or keisari ("emperor"). Other sources give "ship wharf."LambayLamb-eylamb islandReachrainn—LeixlipLax Hlaupsalmon leapLéim an BhradáinThe Irish is a translation of the Old Norse.The English is an Anglicisation of the Old Norse.Oxmantown--Baile LochlannachScandinavian homestead.SalteeSalt-eysalt islandNa SailtíThe Irish is a Gaelicisation of the Old Norse.The English is an Anglicisation of the Old Norse.SelskarSelr-skar seal skerrySeilsceir SmerwickSmjǫr-vík butter bayArd na CaithneStrangfordStrangr-fjǫrðrstrict or narrow fjordLoch Cuan—SkerriesSkeriskerriesNa SceiríThe Irish is a Gaelicisation of the Old Norse.The English is an Anglicisation of the Old Norse.The SkerriesSkeriskerriesNa SceiríLocated in County Antrim.TuskarÞurs-skergiant rockAn Tuscar—WaterfordVeðra-fjǫrðrram or wether fjordPort LáirgeThe English name is a folk etymology.WexfordVeisa-fjǫrðrmuddy fjordLoch GarmanThe Irish was historically anglicised as Loughgarman.Lacy, Thomas. Sights and Scenes in Our Fatherland. Simpkin, Marshall & Co., 1863. Page 404.WhiddyHvít-øywhite islandFaoide Uncertain etymology.WicklowVíkinga-lágVikings' low placeCill MhantáinThe Irish was historically anglicised as Kilmantan.

Names of English origin After the Norman invasion of Ireland, which began in 1169, Anglo-Norman and English language placenames emerged in the areas under Anglo-Norman control. Most of these are within the bounds of "The Pale" – the area that stayed under direct English control for the longest, and where English language and culture held sway. It stretched along the east coast from Dundalk in the north to Dalkey in the south.

Between 1556 and 1641, during its "conquest of Ireland", the English colonised parts of the country with settlers from Great Britain. This is known as the "Plantations of Ireland". After the 1601 Battle of Kinsale defeat in which the Gaelic aristocracy fled to continental Europe the northern province of Ulster was the most heavily colonised. Those who settled as part of the "Plantation of Ulster" were required to be English speaking made up mostly of Lowland Scots and some northern English. The result is that northeast Ulster also has a great number of English-derived placenames.

Such placenames often refer to buildings and other manmade features. They often include forms such as -town, -ton, -ville, -borough, -bury, bridge, mill, castle, abbey, church, etc. However, forms such as hill, mount, mont, wood, bay, brook etc. are not uncommon.

Some placenames that seem to come from English are in fact anglicized Irish names modified by folk etymology. Examples include Longford (), Upperland (from Áth an Phoirt Leathain meaning "ford of the broad (river) bank"),Toner, Gregory: Place-Names of Northern Ireland. Queen's University of Belfast, 1996, Golden (from gabhailín meaning "little river fork") and Forkhill (from Foirceal meaning "trough").Newry & Mourne Council Area, Northern Ireland Place-name Project

Names of Scots origin