Kelly As An Irish Name – Popularity And History

In the rich history of Ireland and Irish emigration to the United States, Kelly is one of the most prevalent Irish last names.

Records show that Kelly has been the second most common surname in Ireland for over one hundred years. It also ranks second in Irish last names in the United States in modern and 19th-century census records.

Kelley, O’Kelley, and O’Kelly are alternate spellings of the Irish surname.

This is an exploration of the Kelly surname from the mid-19th century to the present day. Census records, population surveys, and passenger lists uncover the patterns of this very Irish last name.

How Common Is The Kelly Surname In Ireland?

I’ve researched the population statistics from current times back to the late 19th century. The surname Kelly is consistently the second most common name in the country.

Kelly In Recent Years

Ireland’s Central Statistics Office published the ten most common surnames of babies born in 2022.

Kelly was second on the list. Here are the top five names in descending order.

You can read more about the other top names here:

Population Estimates In The 1990s

Irish genealogist Seán J. Murphy studied popular surname numbers in Ireland and Northern Ireland between 1992 and 1997 based on entries in telephone books.

Kelly was the second most common name in this decade. This bar chart shows the top five.

Kelly In The Early 1900s

The Irish government archives hold full censuses for 1911 and 1901.

As you can see from this table, the Kelly family name was the second most common in Ireland at the beginning of the twentieth century.


 There were approximately 45,800 bearers of the name Kelly on the island of Ireland in 1911.

The number was a little higher in 1901 when about 46,300 people named Murphy were recorded.

Population Estimates In The 1890s

Sir Robert Matheson published a study of Irish surnames in 1890 called “Special Report on Surnames In Ireland.”

Kelly is the second highest ranking name in the survey. This bar chart shows the top five names:

How Common Is The Name Kelly In The United States?

The United States publishes census details up to recent decades.

For privacy reasons, the 2010 census only provides high-level totals of surnames in the entire country. But that’s exactly what we need for this article.

Kelly In The 2010 U.S. Census

Based on the 2010 U.S. census, the name Kelly is the second most common Irish name in America with 267,394 bearers.

It is only behind Murphy, which had 308,417 bearers.

But the situation changes when we take alternate surname spellings into account. I identified four variants of Kelly in the 2010 census:


But the total variants of Murphy (with Murphy and McMurphey) come to 313,387.

Because Kelley with an “e” has over 140 thousand bearers, this pushes the total numbers ahead of all the variations of Murphy.

I’ll summarize by saying this:

Kelly is the second most common Irish name in the U.S. behind Murphy. However, when alternate spellings like “Kelley” are included, the Kelly variants are collectively the most common.

Kelly In The 1940 U.S. Census

The same pattern occurs in 1940 in the census taken the year before America entered the Second World War.

Kelly is the second most common name in 1940 in the U.S. with 151,379 bearers. Murphy was ahead with 184,942 bearers.

But the 80,000+ people named Kelley pull the name ahead when spelling variations are included.


Kelly In The 1870 U.S. Census

Let’s jump back another seventy years to the first census taken after the American Civil War.

Kelly was the second common Irish name behind Murphy in the 1870 census with 67,627 bearers.

However, when the alternate spellings of both names are taken into account, the versions of Kelly were more numerous than the alternates of Murphy.

Here is the breakdown of the Kelly spelling variants:


Kelly Emigration After The Irish Famine

Traditionally, Irish people have emigrated to England, Australia, New Zealand, Canada, and the United States.

The largest wave of emigration to the United States occurred during the 19th century. The peak was in response to the Great Irish Famine, which took place between 1845 and 1852.

This is clearly illustrated when looking for the Kelly name in the shipping passenger lists arriving into New York during this period.

I plotted the numbers for the top three Irish names from 1845 (the start of the famine) to 1854. Kelly is shown as the green line in the line chart below. It is the second most common name amongst the passengers of Irish origin.

Famous People With The Kelly Surname

These are some of the most famous Kellys in recent history:

  • James Kelly (1760-1819): American politician from Pennsylvania who was a lawyer before serving two terms in the House of Representatives as a Federalist.
  • William Kelly (1811-1888): American inventor who influenced modern steel production.
  • Ned Kelly (1854-1880): Son of an Irish convict transported to Australia. Ned became the most famous Australian outlaw in history, with some seeing him as a folk hero and others as a villain.
  • Michael “King” Kelly (1857-1894): King Kelly was an American baseball player who was an early innovator of the hook slide and the hit-and-run.
  • Seán T. O’Kelly (1882-1966): Deputy Prime Minister of Ireland before serving as second President o the state.
  • Oisin Kelly (1915-1981): Irish sculptor whose work can be seen in Dublin’s Garden of Remembrance (the Children of Lear sculpture) and in the capital’s main street (the statue of James Larkin).
  • Grace Kelly (1929-1982): American actress who starred in three Hitchcock films before marrying Prince Rainier of Monaco and becoming Princess Grace. The parents of her father, John Kelly, emigrated from County Mayo. John was also known as Jack Kelly, the first rower to win three Olympic gold medals. His son John became president of the U.S. Olympic Committee.
  • Robert Kelly (1935- ): American poet with over fifty published works of poetry.
  • Francis Kelly (1938-2016): Better known as Frank Kelly, this Irish actor became a household name in Ireland for his role in the TV comedy series Father Ted.
  • Thomas Kelly (1939- ): Awarded the Medal of Honor during the Vietnam War for protecting his unit while severely wounded.
  • Mary Pat Kelly (1944- ): American writer, who writes fiction and non-fiction. Two novels by Mary Kelly are based on her Irish ancestors.
  • Michael Kelly (1957-2003): American journalist who was killed in the Iraq War.
  • Brian Kelly (1961- ): American football coach who coached Notre Dame from 2010 to 2021.
  • Michael Kelly (1969- ): American actor with roles in tv series like House of Cards and The Sopranos.

Kelly Surname: Meaning And Origin

Kelly comes from the Gaelic surname “Ó Ceallaigh” or “Mac Ceallaigh”.

In Irish, Ó means “descendant of” and “Mac” means “son of”. Ceallaigh is a form of the personal name Ceallach. So, the original Gaelic form is “descendant of Ceallach”.

Ceallach has several meanings. Some scholars translate it as “bright-headed” while others translate it as meaning “troublesome”, “strife”, or “war”. Some point to the related word cill which means a churchyard and suggest that Ceallach refers to frequenting churches.

The Anglicization of names in Ireland under English influence led to Ó Ceallaigh becoming “O’Kelly” or “Kelly” because of the similar sound of the words.

Kelly History

There is a legend that the O’Kelly clan descend from one of three chieftain brothers in the fourth century. The brothers were banished to Scotland after killing their uncle, the High King of Ireland. When they returned, they battled the King of Ulster and took a portion of his lands.

One brother became the first king of the new territory. King Colla da Crioch is said by some to be the ancestor of all the Kelly families. He died some time in the mid-4th century.

As these stories are before written manuscripts, we are dealing with legends handed down through poems and songs. Due to Medieval manuscripts, we can be more sure about chieftains and events in the Middle Ages.

Medieval Times

There were several prominent families that took the Kelly surname in the 10th and 11th centuries.

Perhaps the most powerful were the O’Kellys of Ui Maine, a territory in the west of Ireland covering mid Galway and south Roscommon. One of the chiefs, Tadhg Mór Ó Ceallaigh, fought and died with Brian Boru in the Battle of Contarf in 1014.

You can read more about Tadhg Mór in our separate history of the Kelly clan.

Like other Irish clans, the influence of the Kelly chieftains waned after the Anglo-Norman invasion of 1169.

O’Kellys Welcome

William Buí O’Kelly was a chief of the the Ui Maine in the 14th century. He is said to have died in 1381.

In 1351, this chieftain celebrated Christmas by inviting all the poets, storytellers, and musicians from the length and breadth of Ireland to his castle in Roscommon. The gaiety lasted for a full month.

His hospitality became immortalized as an O’Kellys Welcome.

Family Coat Of Arms And Motto

There are several versions of a Kelly coat of arms. This is one example:

The family crest shows two lions on opposite sides of a tower. In heraldry, each is known as a “lion rampant” due to the standing pose on hind legs.

The lions symbolize strength and the tower represents wealth.

The family motto is often found written beneath the crest. The Latin phrase can be translated as “God is my tower of strength”:

Turris Fortis Mihi Deus

Sources For This Article

External Research

The top ten birth numbers in Ireland for 2022 are published by the Central Statistics Office.

The Ireland 1990s estimates are from Seán J. Murphy’s research paper.

The population estimates of 1890 are based on the “Special Report on Surnames in Ireland“, originally published in 1909.

The population figures for the 2010 U.S. Census come from a file provided by the U.S. Census Bureau.

Internal Research

Some of the population numbers are based on my own research and calculations using online archives. I’ve rounded those numbers to the nearest 50 to account for transcription errors and other technical issues with online databases of this type.

The Irish census estimates for 1901 and 1911 are my calculations based on the Irish National Archives.

I plotted the emigration figures from 1845 to 1854 based on calculations from the archives of the New York Passenger Lists (1820-1957).