Aiden in all its spelling variations is the Anglicized version of the Irish Aodhán, which was originally a pet form of the Irish name Aodh (pronounced 'ee'), who was the old Celtic god of the sun and fire. St. Aidan was a famous seventh century Irish saint, noted for his kindness and generosity and for spreading Christianity.
 
Aiden has been a spectacular name success story—especially if you add all its various spellings together. Counted together, Aiden in all its versions is still a Top 10 boys' name.
 
The Aiden spelling has become the predominant version of the name in the US, followed by Ayden -- and then, in order of popularity, Aidan, Adan, Aden, Aydin, Aydan, Eiden, Aidyn, Eydan, Eyden, Adin, Aedan, and Aiyden. And then there's a pack of popular rhyming offshoots such as Brayden and Kaden.
 
Irish actor Aidan Quinn introduced the name to the US. The Aiden spelling was used by actress Tracey Gold and Rod Stewart for their sons.

Aiden

In this country, more recognizable with the Alistair spelling. 

Alasdair

A surprisingly rare form of Arthur that rings more Scottish, and lends itself easily to Art as a nickname.

Artair

This now-popular name has spawned several different spellings. Many parents choose it solely for its style and sound, but we like the history behind this version: the bradan feasa is the "Salmon of Knowledge" in the legend of Finn McCool. 

Bradan

Branigan, also spelled Branagan or Brannigan, is an Irish name full of energy and cheer. It was the title of a 1975 John Wayne movie, and Zapp Brannigan is the antihero of the animated sitcom "Futurama." 

Branigan fans might also want to consider such related <a href="https://nameberry.com/baby-names/168/irish-names">Irish names</a> as Brennan and Breccan, Rafferty and Finnegan.

Branigan

This Irish name of a saint from the Isle of Aran also appears in myth and fantasy fiction, giving it an intriguing, mystical air. 
 Some modern parents are attempting to update the spelling, as in the actor Breckin (middle name Erin) Meyer or the most popular form of the name, Brecken.

Breccan

Brecken is a fresh, distinctively Irish alternative to similar-sounding (and much more popular) Beckett or Beckham. While Brecken is a spelling variation of the original Breccan, it's the most popular form of the name. By whatever spelling, it's a name we'll likely see rise in popularity.
 Spelled Breckin, it's the given name of actor Meyer, known for Road Trip and Rat Race.

Brecken

Callen is a unisex Gaelic name growing in popularity here.  Its newfound trendiness is possibly related to the Chris O'Donnell character on "NCIS: Los Angeles", known only as G. Callen.  Jazz musician Cal Tjader's full name is Callen.

Callen

Carson is one of the most long-running popular <a href="https://nameberry.com/unisex-names">androgynous baby names</a>, with a dash of the Wild West via the legendary Missouri frontiersman Kit Carson. Dating back to when it was the name of Nancy Drew's Dad, Carson is still steadily in the Top 200 <a href="https://nameberry.com">baby names</a>.
 Current Carsons include TV personalities Carson Daly and Carson Kressley, and Pro Bowl quarterback Carson Palmer. Carson Wells was the bounty hunter character played by Woody Harrelson in No Country for Old Men, and Carson is the name chosen by actress Kathryn Erbe for her son.
 Although its best known namesake is writer Carson McCullers, Carson has not caught on as a <a href="https://nameberry.com/girls-names">girl's name</a>.

Carson

Cashel is one of the many appealing <a href="https://nameberry.com/baby-names/168/irish-names">Irish names</a> that have not yet emigrated to the US. Cashel was chosen by actor Daniel Day-Lewis and his writer-director wife Rebecca Miller for their son. 
 In Ireland, Cashel refers to a circular stone fort. It is the name of a town in Tipperary and the protagonist of the George Bernard Shaw novel Cashel Byron's Profession.
 The Cash sound feels especially contemporary and appealing now, with Cashel joining such stylish brothers as Cassius, Cassian, and Cash.

Cashel

The name of an ancient Irish saint is in the contemporary Irish Top 50. While it's one of the rare <a href="https://nameberry.com/list/328/irish-baby-names-for-boys">Irish names for boys</a> that hasn't immigrated to the U.S., it may follow brothers Aidan and Declan to our shores. The t is not pronounced.

Cathal

Cedric was invented by Sir Walter Scott for the noble character of the hero's father in Ivanhoe, presumed to be an altered form of the Saxon name Cerdic. The name was later also given to Little Lord Fauntleroy, the long-haired, velvet-suited, and lace-collared boy hero of the Frances Hodgson Burnett book, who became an unwitting symbol of the pampered mama's boy.
 Since then that stereotype has been broken principally by the handsome Harry Potter character Cedric Diggory, played by the teen-aged pre-Twilight Robert Pattinson, and it, like cousin Cecil, is at the point of being rediscovered by cutting-edge namers.
 Actor and comedian Cedric the Entertainer has propelled this name into the spotlight in recent years.
 Cedric has been on and off the charts the last few years, but is currently back in the Top 1000 in 2022.

Cedric

Extremely popular in Ireland, Ciaran is also well used in England and is beginning to be adopted by parents in the U.S., though usually via the more American-friendly Kieran spelling. The Irish spelling is, however, becoming more familiar on this side of the Atlantic, due to the rising popularity of Belfast-born actor Ciaran Hinds.
 Although it was the name of twenty-six saints in Ireland, Ciaran was not used as a secular name there until the 1950s.

Ciaran

Colm is a popular <a href="https://nameberry.com/list/328/irish-baby-names-for-boys">Irish name for boys</a> that could immigrate, especially with its peaceful meaning. Colm Toibin is a contemporary Irish novelist and critic, author of The Master and Brooklyn; Colm Meaney is an Irish actor. Pronunciation is two syllables instead of one, like Colin with an 'm' at the end. Colm is related to Columba, Colom, Colum, Callum, and Malcolm.

Colm

Both offbeat and upbeat, this evocative traditional Irish name that runs through Celtic mythology is known here via award-winning novelist Cormac McCarthy (born Charles). The author's adopted name is related to Cormac Mac Airt, one of the great legendary high kings of Ireland.
 In two of the Harry Potter movies, Cormac McLaggen is a Gryffindor student.
 And for all you popularity-phobes, Cormac has never yet made it onto the American Top 1000 list.

Cormac

Corwin is an upstanding surname name that has been seen occasionally as a first in literature, but rarely in real life. But maybe with the recent acceptance of Darwin, that might change.
 In the Water trilogy, Corwin appears as a teenage Merlin, and Prince Corwin is a main character in the the Chronicle of Amber series by Roger Zelazny.
 Alternate definitions of the name are 'leather worker' and 'lives near a white enclosure or castle.'
As a family name, it's associated with screen and radio writer Norman and Animal Planet host Jeff.

Corwin

Darren and wife Sharon shop for fifties memorabilia on eBay. The Connecticut place-name Darien might offer an update. 

Darren

Darrin

Declan is the Anglicized form of the Irish name Deaglán. St. Declan was one of the first missionaries to bring Christianity to Ireland, preceding St. Patrick. Originally from Wales, he founded the monastery of Ardmore in Ireland.
 
Declan, the amiable and appealing name of an Irish saint (and the real first name of singer Elvis Costello), is very popular in the Emerald Isle and beginning its certain climb to popularity here, after debuting on the American list in 1998. Like Aidan and Liam, Declan is shaping up to be an American hit.
 
Declan Porter is a current character on Revenge. 
 Cyndi Lauper spelled her son's name Declyn.

Declan

Devilishly handsome, Devin arrived as Kevin was moving out. Not to be confused (though it often is) with the English place-name Devon. While both Devin and Devon are flagging somewhat for boys, the names have dropped out of the Top 1000 for girls, making it more a masculine and less a unisex name these days.

Devin

This authentic form of the name of an Irish mythological hero with the power to make women fall instantly in love with him would work far better here as the Anglicized Dermot. 

Diarmaid

This genial Irish surname feels much more current than Donald. 

Donahue

Finnian is a fair jig of a name, energetic and easy on the ear. Finnian (and brother Finian) is also familiar in its alternate spelling through the classic 1968 Broadway musical Finian's Rainbow, later made into a film starring Fred Astaire as Finian McLonergan.
 There is also a St. Finnian who was a famous teacher and scholar.
 We think Finnian/Finian could really catch on in the wake of cousins Finn and Finlay/Finley.

Finnian

Flynn, a charming Irish surname, is still used only quietly, despite its easygoing, casual cowboy charm, unlike Finn which is a star of this genre. Flynn was the choice of Orlando Bloom and Miranda Kerr for their baby boy, and is also the middle name -- used as his first -- of a son of Miranda's fellow supermodel Elle Macpherson, of Gary Oldman's son Gulliver and Marley Shelton's daughter West.
 Flynn Rider (born Eugene Fitzherbert) is the dashing animated hero of the Disney film "Tangled." On TV's "Breaking Bad", Flynn was what young Walter Jr. tried to rename himself. The name was long associated with the swashbuckling Errol Flynn, inspiration of the phrase "in like Flynn." Some may connect this name to controversial former National Security Adviser Michael Flynn
 Flynn entered the U.S. Top 1000 in 2011, and is a highly popular choice in Australia and New Zealand.

Flynn

The name of a historic Irish leader, Gannon has a solid, yet spirited feel. It was one of the fastest-rising names of 2014, but that trend didn't continue. One pop culture influence was the name of Teen Mom 3 son Gannon Dewayne McKee.

Gannon

After being one of the hot upscale surnames of the nineties, Garrett has left the Top 100 and this streamlined spelling is dawdling near the bottom of the Top 1000. 

Garret

This name of the courteous Knight of the Round Table, the nephew of King Arthur, has long been superseded by its Scottish form, Gavin. 

Gawain

Following in the footsteps of popular brother Brady, Grady is another lively, ebullient Irish surname name. The O'Gradys (originally O Gradaugh) were an ancient clan that produced an impressive number of bishops.
 Perhaps the most remarkable O'Grady descendant is Muhammad Ali, whose mother's maiden name was Grady.
 Tampa Bay Rays outfielder Grady Sizemore was born Gradius.

Grady

Iain, this authentic Gaelic form of John, has been well used in Scotland since the early twentieth century, used concurrently with the shortened Ian spelling, but is rarely seen in the US. 
 Iain Banks and Iain Sinclair are respected contemporary Scottish novelists.

Iain

Kavanagh, which can also be spelled Cavanagh, Cavenagh, Kavanaugh, and Cavanaugh, is one of the few traditional Irish surnames not to start with Mc or O'.  Kavanagh relates to the name first Kevin or Caomhan.  Early kings of Leinster bore the name Kavanagh.

Kavanagh

Nearly unknown outside the British Isles, this old Scottish variation has a sleek surname feel that can make an excellent update of the flagging Christopher.

Kester

Kevan

Killian – aka Cillian – is a spirited yet resonant Gaelic name that was borne by several Irish saints and could make a distinctive replacement for the dated Kelly. Kylian is another spelling that's gaining traction, thanks to French soccer star Kylian Mbappé. Possible downsides: an unsavory first syllable and a connection to the trendy brew. 

Killian

Lachlan is as Scottish as haggis and tartan plaid kilts—a favorite used throughout England, Scotland, Australia, and New Zealand—and just beginning to be noticed in the US: it reached the Top 1000 for the first time in 2013. An ancient name, Lachlan was originally used to describe the Viking invaders of Scotland, those from the land of the lochs.
 Americans and Australians tend to pronounce the first syllable of the name like Lock, but the genuine Scottish pronunciation sounds more like Lack.
 In Ireland, the name was Anglicized as Laughlin; in Scotland the pet forms are Lach, Lachie, or Lockie.
 Lachlan has been a top name in Australia for at least a decade. It has been in the headlines recently via the eldest son of media mogul Rupert Murdoch.
 Somewhat surprisingly, Lachlan has US presidential cred, as the son of tenth president John Tyler, whose other children included Lyon, Letitia, Tazewell, and Pearl.

Lachlan

Lorcan is a name rich in Irish history as belonging to several kings, including the grandfather of the most famous high king of Ireland, Brian Boru. Lorcan O'Toole, known in English as Laurence O'Toole, is the patron saint of Dublin, so it's not too surprising that Irish-born actor Peter O'Toole named his son Lorcan.
 In the Harry Potter epic, Lorcan is the twin son of Luna Lovegood Scamander.
 Strong, easy to pronounce and spell, Lorcan is an Irish name that would stand out from the more common crop of Connors and Liams.

Lorcan

A strong, attractive surname name with a mix of possible origins: either from the Welsh first name Meuric,which is a form of Maurice, and contains Germanic elements meaning fame and power, or from a Scottish Gaelic word meaning a fork in a river or a road, which led to the name of several places named Merrick in Scotland. The Supreme Court saga of Justice Merrick Garland almost certainly caused the bump in popularity that propelled Merrick to its US Top 1000 debut in 2016.
Despite its ancient history, Merrick these days sounds more modern than the somewhat tired Derek.

Merrick

Always the top spelling of the name; Neil peaked in the 1950s, but then enjoyed a second coming following the fame of such Neils as astronaut Armstrong and singers Sedaka, Diamond, and Young. Now semiretired. 

Neil

Possible Gaelic alternative to Kevin and Devon. 

Nevin

Niall is pronounced nye-al--something like Neil, but this Irish spelling of the name makes it much more current and cool.
 This is an ancient name borne by several of the high kings of Tara, the most famous of whom was the powerful semi-mythological fifth century king known as Niall of the Nine Hostages, ancestor of all the O'Neills and MacNeills that followed.
 Niall Ferguson is a respected English historian, one of Time magazine's 100 Most Influential People in the World in 2004.

Niall

Quinn is an engaging Celtic surname that is still on the rise for girls but beginning to flag for boys. As a female name, Quinn is in the Top 100, used for over 3000 baby girls last year, but toward the bottom of the Top 500 for boys, given to 700 baby boys.
Pop culture was an important influence on Quinn's popularity for both genders. Quinn started leaning decidedly toward the feminine thanks to a female cheerleader character on the television show Glee. For boys, Quinn's popularity was influenced by "The Mighty Quinn," the name of a movie, a band, and a Bob Dylan song. 
 Sharon Stone has a son named Quinn. Other ideas for boyish names like Quinn: Quinton, Quincy, Finn.

Quinn

Has a legitimate first name history in its native land and an appealing meaning, but pronunciation is far from obvious. 

Riordan

From India, but feels like an Irish surname (and can in fact be a variation of Rowan), so a possible cross-cultural choice. 

Rohan

Ronan is the compelling legendary name of twelve Irish and Scottish saints that is now drawing some deserved attention; this cousin of the ascending Roman and Rowan was chosen by actor Daniel Day-Lewis and his writer-director wife Rebecca Miller in 1998, and more recently by actress Catherine Bell.
 Ronan is a Harry Potter name—that of a centaur who lives in the Forbidden Forest. Ronan Keating is an Irish singer, Ronan Farrow is a TV personality and Hollywood scion, and its presence as a surname is represented by young actress Saoirse Ronan.

Ronan

With its gentle sounds and earthy vibes, the name Rowan feels like a fusion of different styles. A word name, a surname, and a gender-neutral name, Rowan is rustic but trendy, blending the vibes of both Owen and Oakley. 
Just as it’s hard to fit Rowan into one category, it’s equally difficult to identify one definitive root. It could be considered an Anglicized form of the Irish name Ruadhán, meaning “little redhead” and it was used as an English surname before it became a given name. 
Alternatively, it could be linked to the rowan tree, whose name derives from Old Norse and means “to redden.” In folklore and mythology, rowan trees are seen as a symbol of protection and of life, adding extra meaning to Rowan. 
 To complicate matters further, some scholars identify Rowan as a girls’ name, deriving from Rowena and Rhonwen, meaning “famous friend” or “white spear.” This gives it solid credentials as a unisex name and lends it a slightly more rugged vibe. 
What is certain, however, is that Rowan has quickly become a stylish choice, chosen for over 3000 boys every year. Once an obscure name in the US, it rapidly climbed the charts during the 2010s and has now entered the Top 100 Boy Names for the first time. 
Rowan is popular in the UK, Canada, and the Netherlands too, but even more so among Nameberry users, where it ranks in the <a href=“https://nameberry.com/popular-names/nameberry/boys/allNameberry Top 1000”> Nameberry Top 30.</a> 
The most prominent bearer of the name is probably Rowan Atkinson, the British comic actor of Blackadder and Mr Bean fame. Other namesakes include the former Archbishop of Canterbury, Rowan Douglas Williams, and the Australian swimmer, Rowan Crothers. Pokémon fans and Sarah J. Maas readers might recognize it too as the name of a character in both the game franchise and in the Throne of Glass series. 
Gentle but powerful, stylish but not oversaturated, Rowan may well continue to climb the charts, so if you love Rowan but want to stray from the trends, Ruan, Sylvan, Lorcan, Lennox, Wren and Sloan might inspire you.

Rowan

Parents who have tired of Sean are now contemplating Seamus, the Irish form of James, which has a lot more substance and verve.
 One of the name's most famous bearers is the 1995 Nobel Prize-winning Irish poet Seamus Heaney. Seamus is also a Harry Potter name—Seamus Finnigan is a half-blood wizard friend of Harry's.
 At a time when the police force was predominantly Irish, "shamus" became a slang term for a detective.

Seamus

Shane ambled into the picture via the 1953 movie, adding a cowboy twist to its Irish essence. Shane is even more popular in Ireland than in the USA or the UK.
Singer Siobhan O'Connor and actor Kevin Sorbo have sons named Shane. 

Shane

This unusual Welsh mythological name just might appeal to architect parents wishing to honor Frank Lloyd Wright, who called his two famous residences Taliesin and Taliesin West. 

Taliesin

Tiarnach

Tiernan is the slightly edgier and sharper cousin of Kiernan. This is one Irish surname that is attractive but distinctive; Tierney is another, related, option. 
 Tiernan was a popular name in early and medieval Ireland and was borne by several kings and saints. It is currently high on the list in Northern Ireland.

Tiernan

Tristan -- known through medieval legend and Wagnerian opera -- has a slightly wistful, touching air. This, combined with the name's popular "an" ending, makes Tristan very appealing to parents seeking a more original alternative to Christian.
 One influence was the character Tristan Ludlow played by Brad Pitt in the 1994 movie Legends of the Fall, based on a Jim Harrison novel.
 Tristan is a dragon-slaying hero of Celtic legend, whose story was incorporated into Malory's Le Morte d'Arthur, in which Tristan is one of the Knights of the Round Table, consumed by his doomed love affair with Queen Isolde. Wagner set the story to music in his opera Tristan und Isolde.
 Tristan and its alternate form Tristram have been found in later lit as well. Tristram Shandy is a famous early comic novel by Laurence Sterne (in which the hero's father calls Tristram the worst name in the universe); Tristan is a major character in James Herriott's All Creatures Great and Small, and there is an eponymous novella by Thomas Mann.
 Particularly popular in Canada, Tristan was chosen for their sons by Travis Tritt, Wayne Gretzky, Natasha Henstridge and, most recently, by Elsa Pataky and Chris Hemsworth. Basketball player Tristan Thompson hails from Canada.
 Other variants of Tristan include Tristen, Tristin, Triston and Tristian.

Tristan

MarissaMichelle's list "Celtic Boy Names" of 50 great name ideas: Aiden - Tristan!