Then Maggie O'Connor took up the job, "Biddy" says she "you're wrong, I'm sure" Biddy gave her a belt in the gob and left her sprawling on the floor Then the war did soon engage, t'was woman to woman and man to man Shillelagh law was all the rage and a row and a ruction soon began
—Tim Finnegan's Wake, traditional Irish ballad
Ireland, the land of ire.
The Irish, or at least Oirish, counterpart to the Violent Glaswegian (when there's even any difference at all). Characters who are Irish or are of Irish descent are often portrayed as being fond of physical confrontation; even in a work where violence is typical, Irish characters will be especially eager for it. Being intoxicated and/or in a bar will often accentuate these tendencies.
This can be played many ways. A good-natured Boisterous Bruiser who favors his fists is typical of many recent examples; boxing has a long history in Ireland and among Irish-Americans. Negative portrayals are more common the farther back you go. More thuggish examples will often carry a shillelagh, a traditional knobby cudgel that has become a symbol of Irish culture as well as its violence. Even darker examples might be remorseless Blood Knights, tyrannical bullies, or terrorist psychopaths. If a Fighting Irishman is or was in the Irish Republican Army expect him to have at least a bit of the Mad Bomber thrown in.
This may very slowly be becoming a Discredited Trope; while in the 19th century Irish soldiers did indeed make up a disproportionate number of soldiers in the British and American armies (and are still allowed to join the British Army) times have moved on even if the stereotype hasn't. Ironically, Ireland is one of very few countries to become independent in the 20th century to have never been in an international war. During World War II it remained neutral and turned down a 1949 offer to join NATO. In fact, the Irish military has a good reputation as peacekeepers. The island also has a low rate of violent crime by international standards. In recent years, Irish boxers have had success at the Olympic Games.
The Trope Namers are the University of Notre Dame's varsity sports teams and their belligerent Leprechaun mascot, who in turn got the name from Father William Corby, who was twice as President of the University of Notre Dame and served with the "The Fighting Sixty-Ninth" 69th New York Infantry Regiment, an Irish regiment during the American Civil War.
Irish girl Clover in the comic Blue Monday is easily the most violent person in the entire comic.
Matt Murdock, a.k.a. Daredevil is the biggest example of this trope in comics. The son of an Irish-American boxer, Jack "The Devil" Murdock, Matt Murdock prowls the rooftops of Manhattan's Hell's Kitchen neighborhood as Daredevil. He's an expert martial artist and boxer, and generally not someone you'd want to face in a fight. Matt is also portrayed as being devoutly Roman Catholic, another famous Irish cultural trait.
Hellblazer: His native Liverpool being at least as Irish as Boston in places, John Constantine probably counts, although he isn't really much of a scrapper, preferring to let cockney Chas or Violent Glaswegian Header handle that sort of thing. His girlfriend Kit has some boisterous friends, but they're more boozers than bruisers.
Steve Rogers, better known as Captain America, was born to poor Irish immigrants.
The ex-IRA terrorists of Sin City are a much darker example.
In The Quiet Man, everyone is itching for a fight between Thornton and Danaher, and when it finally comes, they all want to join in.
(Irish-American) director John Ford loved this trope, usually playing it in the lovable Boisterous Bruiser variation and frequently involving alcohol. In his cavalry pictures there is usually at least one Sergeant of this type, in Fort Apache you have three, with only the sober Sergeant-Major O'Rourke an aversion. In She Wore a Yellow Ribbon they get into fights with fellow rankers from another immigrant group, German-Americans.
Inverted in Back to the Future Part III: Seamus McFly keeps counseling Marty about staying out of fights and keeping his cool, although this is probably because his own brother Martin was very much the embodiment of this trope. This didn't end well.
Seamus: Martin used to let men provoke him into fighting. He was concerned people would think him a coward if he refused. Thats how he got a bowie knife shoved through his belly in a saloon in Virginia City.
Crops up in Gone Baby Gone, where a man at the bar in Dorchester where Patrick goes to investigate gets belligerent and refers to him as having an "ass like a Skippy Jar." Amusingly enough, this was a Throw It In and the man was an actual resident of the area, and Ben Affleck, the director, explains on the commentary that they were actually nervous about whether the residents would take direction or get belligerent for real.
Far and Away: Lower-class Irish are shown to be rowdy, with a love of wrestling and fighting. The local Irish-American boss is introduced bare-knuckle boxing for fun, and Joseph Donnelly, the male lead, is a young, hot-headed Irish immigrant who brawls his brothers and ends up fighting for money. This is all contrasted with the upperclass Irish, who behave like typical European gentry.
Mulvaney, the Irishman among Kipling's Soldiers Three (along with Yorkshireman Learoyd and Cockney Ortheris) is certainly a fighter to be reckoned with.
The title character of Kim, real name: Kimball O'Hara, is the son of a soldier in a fictional Irish regiment, the Mavericks. They also appear in the novel and appear to have a reputation in tune with this trope, although it really only comes to the for in one brief scene.
Burn Notice: Ex-IRA fighter Fiona Glenanne is quick to recommend that any problem be solved by charging in with guns and bombs blazing, especially when it involves children being endangered. Her suggestions usually get shot down in favor of something less conspicuous, but when the firepower's needed Fi is always ready to provide.
The whole Reagan clan is definitely a Badass Family, and the adults all seem to be tough fighters. Lampshaded by Great-Grandpa Reagan who responds to one of the kids wondering about what would happen if an intruder broke into the house by saying "Are you kiddin'? He'll take one look around this table and run the otha' way!"
In 30 Rock, Jack Donaghy ends up in a fist fight with members of his dysfunctional family in the appropriately titled episode "The Fighting Irish".
The Colbert Report: Stephen has invoked his Irish heritage several times in connection with his generally aggressive demeanor:
At the end of his first interview with Chris Mathews, who is also Irish-American, Stephen challenged him to a wrestling match and lost.
Stephen has stated on multiple occasions that, if he had a Time Machine, he would challenge Oliver Cromwell to a bare-knuckle fistfight on the banks of the River Shannon because "he drove [his] people west of [the river] to farm on rocks and gravel!"
Saturday Night Live: Patrick Fitzwilliam and William Fitzpatrick, hosts of "Top O' the Mornin'" regularly punched walls.
The ballad "Finnegan's Wake." A fight at a wake leads to the whiskey spilling over the corpse. Being Irish, he immediately rises from the dead to get at the whiskey and joins the fray.
The Garryowen is a song all about drinking and fighting, and fighting and...drinking. And fighting.
The Dropkick Murphys have several songs with this theme, including "Take 'Em Down" "Going Out In Style" and "Cruel", which contains this line:
I was young and I thought I knew everything
It's so hard to change a fool's mind
When you're stubborn by nature and quick to the draw
And you're full of inherited pride
The chorus of "The Irish Drinking Song" by Buck-O-Nine (commonly misattributed to the Dropkick Murphys or Flogging Molly) consists of "We drink and drink and drink and drink and drink and drink and fight" over and over again.
The protagonist of "Clancy Lowered the Boom."
Now Clancy was a peaceful man If you know what I mean, The cops picked up the pieces After Clancy left the scene, He never looked for trouble That's a fact you can assume, But never-the-less when trouble would press Clancy lowered the boom!
Finlay, who "loves to fight", embodied the fun-loving Boisterous Bruiser side of this trope, even as he knocked people out with his shillelagh.
"The Celtic Warrior" Sheamus represented the more villainous side, as he is willing to inflict serious injuries through underhanded means. After his Heel-Face Turn he's stopped using sneaky tactics and trying to cause permanent injuries, but he can still project serious menace when he wants.
The Fianna from Werewolf: The Apocalypse often danced in this territory as an embodiment of Oirish tropes. This is what happens when you take Fionn Maccumhail's warrior band and make them all werewolves.
The prequel novel Fate/Zero features another Irish Lancer, Diarmuid of the Love Spot, a hero from the Fenian Cycle of Irish mythology, who carves up legions of demonic terrors and fights Berserker hand-to-hand. Unlike Cu Chulainn he's not in it for a fight however, and while he likes fighting as much as any other Servant he's not unusually fond of it.
In one of the St. Patrick's Day episodes of The Simpsons, Springfield's Protestant and Catholic Irish populations remember how much they hate each other when they aren't allowed to drink. Cue orgy of violence.
Another St. Patrick's Day episodes where Bart inadvertantly touches off a riot:
KENT BROCKMAN: Drunkenness, fighting, destruction of property: are these really the qualities we associate with the Irish?
In Family Guy, drunken violence is portrayed as a standard evening's entertainment when Peter travels to Ireland to find his real father.
Parodied when Chris compares the gas induced by his mother's vegetables to an Irish Bar Brawl in his intestines; the Brussels sprout and broccoli argue with Irish accents and fight in front of a crowd of onlookers.
King of the Hill: Peggy rallies the school cheerleaders to beat up a version of the opposing team's Irish mascot by stereotyping as much as possible. Afterward, the act is treated as a hate crime.