Conan O'Brien is well and truly soaking up the best that Ireland has to offer during his visit this week.

The Irish American funnyman was in the famous Dublin pub and venue Whelan's on Thursday night where, of course, he indulged in a bit of a singsong with none other than The Irish Tenors.

"Tonight I sang with The Irish Tenors in Whelan's Pub," O'Brien said on social media on Thursday night.

Ever the jokester, he added: "We did 'Cowboys From Hell' by Pantera."

In reality, O'Brien and The Irish Tenors sang (what else?!) "Danny Boy."

Tonight I sang with The Irish Tenors in Whelan's Pub. We did "Cowboys From Hell" by Pantera. pic.twitter.com/wlZwSufy2R

— Conan O'Brien (@ConanOBrien) January 11, 2024

Whelan's shared a clip of O'Brien and The Irish Tenors singing, noting that it was a "privilege" to host them.

What a privilege to have Conan O'Brien drop in this evening to perform Danny Boy with the Irish Tenors. Unbelievable stuff. #conanobrien

📸 insta/@conchobar.m.l.cinneide pic.twitter.com/iCdfTHMmPq

— Whelan's (@whelanslive) January 11, 2024

The Irish Tenors were impressed with their "fourth tenor," saying that O'Brien "has the chops."

A great night with our fourth tenor last night @ConanOBrien he has the chops . @rtenews https://t.co/TdQVnRcEAC

— The Irish Tenors (@TTenorsmusic) January 12, 2024

Not surprisingly, O'Brien caused a bit of a stir when he visited Whelan's. He was filmed chatting with some people outside the venue, including the music group Dug:

View this post on Instagram

A post shared by DUG (@dugband_)

Despite having the craic in Whelan's on Thursday, O'Brien showed no signs of slowing down on Friday when he shared a snap taken in Dublin of "fairy homes."

These are little "Fairy homes" on a tree in Dublin. Fairies live here until they're 32, and then they're forced out by their parents. pic.twitter.com/j6dzpzKzgx

— Conan O'Brien (@ConanOBrien) January 12, 2024

Meanwhile, Patrick Kielty teased on Thursday that the famous Irish American was set to make an appearance on RTÉ's "The Late Late Show" on Friday night.

On OUR show? Tomorrow night? Don’t even know who you might mean… #latelate pic.twitter.com/5dIlF93n0h

— The Late Late Show (@RTELateLateShow) January 11, 2024

It's unclear how much longer O'Brien will be in Ireland, but he's had a busy schedule this week making stops in Dublin, Galway, Tipperary, and Limerick.

It's believed that he is in Ireland filming for his new travel show "Conan O'Brien Must Go." His previous travel show, "Conan Without Borders," won an Emmy in 2018 in addition to receiving an Emmy nomination the following year. 

O'Brien, a native of Boston, has frequently leaned into his Irish roots throughout his comedic career. In 1999, he filmed a segment in Ireland for "Late Night with Conan O’Brien," which saw him play a clueless American tourist.

O'Brien's ancestors were from Ireland; he once claimed his doctor was stunned to see his DNA showed he was "100% Irish."