Regions of Ireland
- Mealagh River
- McSwynes Bay
- Mayo County
- Mayo
- Maynooth
- Mayne House
- Mayglass
- Mayfield
- Mauricemills
- Maum West
- Maumturk Mountains
- Maumtrasna
- Maum East
- Maumakeogh
- Maum
- Maulyneill
- Mauherslieve
- Maugha
- Mattock River
- Mattle Island
- Mastergeehy
- Massytown
- Massy Lodge
- Mason Island
- Masonbrook
- Lough Mask
- Mary Ville
- Maryland
- Mary Fort
- Marlow House
- Marlay Grange
- Markree Castle
- Marino
- The Marina
- Marble Hill
- Marble Hill
- Manulla Junction
- Manulla
- Mantua House
- Mantlehill
- Mansfieldstown
- Manseltown
- Manorhamilton
- Manorcunningham
- Mannin Lake
- Manning Castle
- Manning
- Mannin Bay
- Mangerton Mountain
- Gap of Mamore
- Mallow
- Mallaranny
- Malin More Head
- Malin More
- Malin Head
- Malin Hall
- Malin Beg
- Malin Bay
- Malin
- Mal Bay
- Malahide Inlet
- Malahide
- River Maine
- Slieve Main
- River Maigue
- Mahoonagh
- Mahonstown House
- Mahonburgh Bridge
- River Mahon
- Lough Mahon
- Lough Magrath More
- Magrath Loughs
- Lough Magrath Beg
- Maginstown House
- Maghery Bay
- Maghery
- Maghera
- Magharee Sound
- Maganey
- Madore Station
- Maddockstown
- Macroom
- Macreddin
- Mac Murrough House
- Macmine Junction Station
- Macmine Castle
- Macklaun
- Mackans
- Mackan
- Lough Machugh
- Macgillycuddys Reeks
- Mace Head
- Maas Upper
- Maas Lower
- Maas
- Maam Cross
- Lyre
- Lyre
- Lyre
- Lyrattin
- Lyrath House
- Lyracrumpane
- Lyons House
- Lynnbury
- Lydacan House
- Lusk
- Lurgy River
- Lurga Point
- Lurgangreen
- Lurganboy
- Lung River
- Lullymore Lodge
- Lukeswell
- Lugnaquilla
- Lugnadeffa
- Log na Brice (mullach thoir thuaidh)
- Lughinny
- Lugglass Upper
- Lugglass Lower
- Luggacurren
- Lugboy House
- Lucan
- Lowville House
- Lowtown House
- Lowtown
- Low Island
- Lowerymore River
- Lowertown
- Louth Hall
- Louth
- Louth
- Louisburgh
- Loughsalt Mountain
- Loughros Point
- Loughros More Bay
- Loughros Beg Bay
- Loughrea
- Loughmoe
- Loughmask Castle
- Loughlohery House
- Loughlinstown
- Loughglinn House
- Loughglinn
- Lough Fea House
- Lough Eske Station
- Lough Eske Castle
- Lougherglass
- Lougher
- Loughcutra Castle
- Loughcrew
- Loughane
- Loughanavally
- Loughananna
- Losset
- Loskeran
- Lorrha
- Lords Harbour
- Looscaun
- Loo River
- Loop Head
- Loo Bridge Station
- River Loobagh
- Lonsdale
- Longwood
- Longueville
- Longtown House
- The Long Range
- Longpavement Station
- Longorchard House
- Long Island Channel
- Long Island Bay
- Long Island
- Long Island
- Longford House
- Longford House
- An Longfort
- Longford
- Longford
- Longfield House
- Longfield House
- Long Bohur
- Lombardstown
- Lohort Castle
- Loghill
- Lodgepark House
- Lobinstown
- Lloydsborough House
- Lixnaw
- Littleton
- Little Sugar Loaf
- Little Slaney River
- Little Skellig
- Little Island Station
- Little Island
- Little Island
- The Little Furze
- Little Foze Rock
- Little Brosna River
- Listry Bridge
- Listrolin