Costello Surname Meaning, History & Origin

Costello Surname Meaning

Costello sounds Italian, but isn’t.  The root of the name is Irish, from Oistealb which is the Gaelic rendering of Jocelyn and in Gaelic is a personal name meaning “resembling a deer.”  Costello is the anglicization of the Gaelic CoisdealbahaighCostello is the main spelling today. A variant in Ireland is Costelloe.

The Jocelyn in question was the Anglo-Norman knight Jocelyn de Angulo who had come to Ireland at the time of Strongbow. His descendants settled in Connacht and adopted the Gaelic name Mac Oistealb or Mac Costello. 

Costello Surname Resources on The Internet

Costello Surname Ancestry

  • from Ireland (Mayo)
  • to America, Canada and Australia

Ireland. The Costello family first appeared on record in Ireland in 1193 when the Annals of the Four Masters recorded: “Inishcloghbran was plundered by the sons of Osdealb.”

The first known holder of the surname was believed to have been Cumumhan Mac Casarlaigh in about 1252; whilst in the ‘modern’ spelling it may have been Teag MacCostello, chief of the clan in 1565.

The family held lands in county Mayo, in the barony of Costello (named for them) in the east of the county, until the end of the 16th century. Much of their time was spent in feuds with the MacDermots, their neighbors. In 1565 the principal seat of the Costellos was at Castlemore near Ballaghadereen.  However, by the time of Cromwell, most of these estates had been confiscated.  

“Dubhaltach Costello, a colonel in the Spanish army, had returned to Ireland after the Restoration and, disappointed by his failure to recover the family estates, devoted the rest of his life to wreaking vengeance on the new Dillon proprietors. Proclaimed a rebel and an outlaw in 1666, he carried out ‘a vendetta of raids and burnings against Viscount Dillon’ until he was shot dead by Dillon’s soldiers in March 1667.”   

The Costello castle at Castlemore had been destroyed and the family had to move to more modest quarters at Edmondstown House in the northern part of the barony.  There they were to remain. In 1864 Arthur Costello built a new house by Edmondstown in the style of a Scottish manor house where he entertained lavishly. However, the expenditure all but ruined him and he died in poverty en route to Dublin, the last of the Costello line.   

The Costello name remains a common surname in Mayo and Galway where it is often spelt with an extra “e” at the end. Costello is also found in Tyrone in Northern Ireland where it has been an anglicization of the Gaelic Mac Coiscle.  Roughly 20% of Costellos in Ireland today are Costelloes.

England. Many Costellos migrated from Ireland to England. The best-known son of this migration, the singer/songwriter Elvis Costello, adopted the Costello name.

America. The Costello name was first stamped on America through Maurice Costello, the son of Irish immigrants Tom and Ellen Costello who had come to Pittsburgh in the 1870’s. Maurice started off in local vaudeville and got his big break in film in 1912.

As he recounted: “I had wealth and a volume of fan mail arriving daily – love notes, mash notes, telegrams asking appointments, telephone calls, gifts, flowers, offers of marriage, everything. I could not help it. I was the first great screen lover, the first star, I belonged to the public.”  

His daughters Dolores, who married the actor John Barrymore, and Helene also became screen stars of the silent era.

Mary Costello had come to Philadelphia from county Mayo in 1867 and, soon after, married fellow immigrant John Kelly.  Her son Jack Kelly was an Olympics rowing gold medal winner, her grand-daughter Grace Kelly the famous actress who became Princess Grace.

Costello in America is often thought to be an Italian name, because of the number of Italian-Americans – such as the comedian Lou Costello and the crime boss Frank Costello – who have adopted the Costello name.

Canada. Thomas and Mary Costello who left their family home in Kerry for Canada in 1825 have a large number of Costello descendants in Canada today. They originally settled in Douglastown on the Gaspe Peninsula. Costellos later moved west to Calgary where they were among its early settlers. Copps Costello was Mayor of Calgary from 1915 to 1919.

Australia.  Two Costellos who came to Australia, John and Patrick Costello, made their mark on their new country, despite adversity.

John Costello arrived with his parents Thomas and Mary from Tipperary to Sydney in 1837. Four of their five children had died during the voyage but John the youngest had managed to survive. His restless nature took him to ranching in Queensland and even to the Northern Territory; but drought, fever, and bush fires took their toll and he eventually settled in the early 1900’s in quieter pastures at Tocabil in western NSW. Michael Costello’s 1930 book Life of John Costello told his story.

Patrick Costello came with his sister Mary as assisted migrants from Leitrim to Melbourne in 1841. His life was to be urban, as a building contractor and local politician. He too had his reverses, being jailed for a year and expelled from Parliament in the early 1860’s for irregularities. He was later encumbered by debt. However, he managed a return to politics in the early 1890’s as Mayor of Melbourne. A descendant is the Australian Federal Treasurer of the 1990’s, Peter Costello.

New Zealand.  John and Ann Costello arrived in New Zealand via Australia from Tipperary in the 1840’s.  They raised nine children on the Coromandel Peninsula on North Island (one of whom, Michael, drowned in a swimming accident). A number of Costellos left Kerry for Invercargill, South Island in the 1860’s.

Costello Surname Miscellany

De Angulo and Costello: From Beginning to End.  The Anglo-Norman knight Jocelyn de Angulo is seen as the precursor of the Nangles and later the Costellos in Ireland.  He arrived with Strongbow in 1170.  It is thought that he was a descendant of an earlier de Angulo who crossed the Channel with William the Conqueror in 1066.  De Angulo translates in the French Norman tongue as “of Angle.”  The family origin may therefore have been the small village of St. Germaine d’Angles near Evreux in Normandy.

As Costellos the family survived the Cromwellian confiscations and lived on for another 250 years.  The last of the line, Arthur Costello styled the Baron de Angulo, died in 1891 in poverty and was buried along the shores of Lough Urlaur in Costello barony.  A flat headstone still marks the grave.

Reader Feedback – Costellos and Castlemore.  I would like to see Castlemore.  It was reputed to have the finest views of Connacht on a clear day. The Costello clan in Mayo had strong links with the area. Costello castle was ceded to Viscount Dillon under the surrender and regrant policy.

Michael Costello (

The Costellos and the MacDermots.  The feuding between the Costellos and their neighbors the MacDermots, gave rise to the Romeo and Juliet love story in the 17th century between Tomás Láidir, the son of the chieftain MacCostello, and Una Bán MacDermot, the daughter of the last chief of that name.

Tomás fell in love with Una Bán and she with him, but neither family would allow them to marry.  Eventually both of them were said to have died of broken hearts.  They were buried in adjoining graves on Trinity Island in Lough Key (visible today from Lough Key Forest Park).

Reader Feedback – Costello as Coisdealbahaigh and in County Tyrone.  Very informative. However, it does not include some vital information, such as the forced anglicization of the Irish Gaelic name Coisdealbahaigh and for that matter all Irish names into Costello.

Nor does it include Costello in Northern Ireland, particularly around Strabane in county Tyrone. In that case Cushley and Costello are the same name.  Both were changed from the Irish Gaelic name Mac Coiscle.  Reference MacLysaught on this crucial piece of Irish history under British rule.

Charles F. Costello (

Reader Feedback – Costelloes in Scotland or Malta?  Do you know of any Costelloes that settled in Scotland in the 1830’s? Or are connected to the isle of Malta?  Kristen Gatt (

Reader Feedback – Costello from Kildare to Kentucky.  My great grandfather Michael Costello emigrated to the US in 1847 from Ireland, we believe from county Kildare.  He settled in Kentucky.  We would love to know more about his family in Ireland.  Jennifer Hughes (

Reader Feedback – Mary Costello and the Kellys in Philadelphia.  There has been a great deal of confusion over the name Costello. Many Americans just assume the name is Italian and many Italian-Americans can become adamant when told it is an Irish name. Growing up in Philadelphia I had Italian-American classmates in grammar school who would ask me if I was ashamed to be Italian after they would hear me say that I am of Irish descent.

We had a famous Philadelphian, Grace Kelly, who was a Costello. Her father’s mother was Mary Costello from Newport, county Mayo. Her father was famous before Grace was born. John B. Kelly Sr. was a gold medal winner in two Olympics at singles and doubles skulls. His doubles partner was his first cousin Paul V. Costello. It really is a fantastic story.

Chuck Costello (

John William Costello in Calgary.  John William Costello left his home near Listowel in Kerry to join his uncle in Eastern Canada in 1862.  Shortly afterwards he was joined by his brother William.  Together they opened a retail store named The Costello Brothers.  But it later went bankrupt.

In 1883 John ventured to Calgary in Western Canada to check it out.  Having decided that the place was to his liking, he sent word back east that his wife and five children, and brother, wife and their five children should join him. The two families duly arrived by train later in the year, both wives being heavily pregnant at the time. Calgary at that time was in its infancy as a town and the two babes when born were the first European babies to be born there.

John was Calgary’s first teacher, starting Bayton Hall, a private school in a small log cabin out in the prairie. He was the father of two medical doctors, an alderman, and a future mayor of Calgary.  He is commemorated in the John Costello Catholic school in Calgary named after him. Calgary had become very much an Irish town in the Prairies.

There are still Costello relatives living in the Listowel area in county Kerry.  William, uncle to John William Costello, remained in Ireland and his descendants are still in possession of the family farm.

Peter Costello on Patrick Costello.  The forebear of the Australian politician Peter Costello was the immigrant Patrick Costello who had come to Melbourne from Leitrim in Ireland on the William Metcalfe in 1841.

Peter wrote the following about his ancestor in his 2009 book The Costello Memoirs.

“Patrick was a successful publican in Melbourne who owned a string of hotels.  He was elected to the city council and later Parliament as a representative of the Publicans’ party.  In his efforts to win one election he apparently paid patrons to vote under assumed names. They were soon discovered and the game was up.  He was convicted of ballot fraud and sentenced to prison, although public petitions led to his early release.

Our family was blissfully unaware of these events until a distant relative wrote a genealogical book that included Patrick.

The discovery of this interesting family history allowed me to make a boastful claim whenever I addressed Irish functions.  Most of the early Irish in America came as convicts.  But my great great grandfather came to Australia as a free man. Our family was so upright and law-abiding that they became convicts only once they got to Australia!”

Costellos from Ireland to New Zealand.  Three Costello brothers – Maurice, Edmund and Denis – were recorded as farming in O‘Dorney parish in county Kerry in the 1820’s.  Four of their children – William, Maurice, Catherine and Jane – emigrated to New Zealand in the 1860’s.  They settled in and around Gore near Invercargill on South Island. William for a time was a hotel keeper in Gore. And there is a Costello’s restaurant in Gore today.

There was one brother Denis who stayed.  His grandson Eugene kept in touch with his New Zealand relatives until his death in 2002. 

Costello as a Chosen Name in America.  Costello sounds Italian, but isn’t.  It’s Irish.  But that didn’t stop a number of Irish-Americans adopting the Costello name in place of their own over the first half of the 20th century.  Costello was probably a more acceptable Italian-sounding name at that time.  There were a number – a comedian, a mobster, a wrestler and a boxer – who adopted the Costello name.

Lou Costello

Louis Cristillo was an American comedian known as Lou Costello and best remembered in the double act of Abbott and Costello.  In his early days he cast around for a suitable stage name.  He in fact fought as a boxer under the name Lou King.  In the end he took his professional name from the silent screen actress Helene Costello who was popular at the time.

Frank Costello

Francesco Castiglia arrived in New York wiith his parents as a young boy in 1900.  As a young boy he joined a local gang and soon adopted the name of Frank Costello.   He rose during the 1920’s and 1930’s to become one of the crime chiefs in New York as head of the Luciano family.  He was known as “the Prime Minister of the Underworld.”

Al Costello

Giacomo Costa was a professional wrestler in Australia best known by his ring name Al Costello.  He was the first professional wrestler to be nicknamed “the man of a thousand holds” because of his innovative and very technical style.  Sicilian-born, he came up with the name of Al Costello, thinking that it sounded tough – a mixture of Al Capone and Frank Costello.

Billy Costello

William Castiglioni, born in upstate New York in the 1950’s, boxed under the name of Billy Costello.  He became the subject about a well-regarded book about boxing by Thomas Hauser.  His younger brother Vinnie Costello was also a professional boxer.   

Costello as a Chosen Name in England.  Elvis Costello was Irish not Italian.  He was born Declan MacManus to Irish parents in London in 1954.  His father was a jazz trumpeteer who sang with the Joe Loss orchestra.   Elvis’s first public appearance was in fact with his father.

In his twenties he became active in the pop rock scene.  Around this time, he adopted the stage name D.P. Costello.  His father had performed under the name Day Costello and Elvis has said in interviews that he took this name as a tribute to his father.  Elvis after Elvis Presley came later.

Costello Names

  • Teag MacCostello, chief of the Costello clan in Mayo in 1565, was the first to bear the Costello name.
  • Maurice Costello, Irish-American born, was a leading figure in American vaudeville in the late 1890’s and early 1900’s. His daughters Dolores and Helene became stars of the silent screen.
  • Frank Costello, born Francesco Castiglia, was an American Mafia crime boss of the 1930’s.
  • Lou Costello, born Louis Cristillo, was one half of the famous Abbott and Costello comedy double act that entertained American audiences in the 1940’s and 1950’s.
  • John A. Costello, born in Dublin, was twice Taoiseach (Prime Minister) of Ireland, in 1948-51 and 1954-57.
  • Elvis Costello, born Declan MacManus, is an English singer/songwriter of Irish roots.

Costello Numbers Today

  • 9,000 in the UK (most numerous in London)
  • 11,000 in America (most numerous in New York)
  • 16,000 elsewhere (most numerous in Ireland)

Costello and Like Surnames 

The Irish clan or sept names come through the mists of time until they were found in Irish records such as The Annals of the Four Masters.  The names were Gaelic and this Gaelic order was preserved until it was battered down by the English in the 1600’s.

Some made peace with the English.  “Wild geese” fled to fight abroad.  But most stayed and suffered, losing land and even the use of their language.  Irish names became anglicized, although sometimes in a mishmash of spellings.  Mass emigration happened after the potato famine of the 1840’s.

Some surnames – such as Kelly, Murphy and O’Connor – span all parts of Ireland.  But most will have a territorial focus in one of the four Irish provinces – Leinster, Munster, Ulster, and Connacht.

Connacht in NW Ireland covers the counties of Mayo, Sligo, Leitrim, Galway, and Roscommon.  Here are some of the Connacht surnames that you can check out.


Click here for return to front page

Written by Colin Shelley

Leave a Reply

Required fields are marked *