MKS star Siobhan Donaghy mixed whisky with Guinness to make the most Irish drink ever. "Seemed like such a good idea at the time," she said.
Emmerdale actor Lyndon Ogbourne also got in on the Guinness. You, er... you've got a little something on your nose, Lyndon.
Mariah Carey donned an emerald green bikini and a temporary shamrock tatt as she spent St Patrick's Day somewhere warmer and more exotic than Dublin.
Khloe Kardashian posed with nephew Mason in a pair of shamrock glasses that we think were inspired by her future brother-in-law Kanye West.
We prefer Pixie Lott's shamrock specs though. She also gets bonus points for the Irish cider.
Denise Van Outen reminisced about that time she gushed about Ireland on stage in Legally Blonde.
scene from Legally Blonde when I played Paulette. Happy St Patricks day! Ireland,country of whisky & Love http://t.co/IfXyOb60QS— Denise Van Outen (@denise_vanouten) March 17, 2014
One Direction's Niall Horan resisted the urge to go all 'Harry Styles' and party on St Paddy's Day, instead having a quiet one with his nephew, Theo.
Irish presenter Laura Whitmore cracked out the face paint and convinced cops in New York to let her walk in the city's St Patrick's Day parade.
B*Witched waved Irish flags, some of its members more enthusiastically than others.
Happy Paddy's Day :) have a great day all!!! pic.twitter.com/15VGp1jifH— B*Witched (@BWitchedreunion) March 17, 2014
Paris Hilton wore green and posed a lot (sans Guinness, may we point out).
Glee star Kevin McHale outed himself as an Irishman and spent St Patrick's Day (which was also his father's birthday) tracking down all the other McHales in County Mayo with his family.
Irish star of The Voice Leah McFall sung "wee folk songs" with none other than Seal! (Beats chucking up black stuff outside Yates's.)
And Justin Bieber...
... Oh. This might be the first time we've ever felt sorry for him.