The Dublin band played the title track of their album 'A Hero's Death'
Irish bands continue to make great strides on international chat shows - take Pillow Queens' recent spot on James Corden's show, for example.
Of course, it's far from Fontaines D.C.'s first appearance on a US TV show, although this is definitely one of their most impressive.
The Dublin band made an appearance on The Tonight Show with Jimmy Fallon the other day, and their rendition of the title track of their second album 'A Hero's Death' was pretty incendiary.
It was filmed in a pub - which several people have pinpointed as The Auld Shillelagh in Stoke Newington, London - and sees frontman Grian Chatten singing the track while having a pint at the bar. That's multitasking for you.
The band are also nominated for a Grammy for Best Rock Album, and for both Irish Album and Irish Song of the Year 2020 at this year's Choice Music Prize.
Watch it below: