And now, Saoirse Ronan sups Guinness and sings 'Fairytale of New York'

Saoirse also tested her 'Bridesmaids' trivia

Saoirse Ronan was on the show to promote her new movie 'Mary Queen of Scots,' which releases in The States this week. She was on-hand to sing a rendition of The Pogues and Kirsty MacColl's classic Christmas song 'Fairytale of New York'.

Now, before you give it a watch, we have to give you a brief warning; Jimmy Fallon attempts a raspy Dublin accent, not too far off Shane MacGowan... but it's actually not that bad. In fact, (dare we say it) it's actually quite good.

Saoirse does a great job too, and they even get a chance to sup on some watery American Guinness. Awh bless.

And if that wasn't enough Saoirse for you, she also turned up for a chat with Jimmy on his sofa.

A mega-fan of the movie 'Bridesmaids' (who isn't?), Saoirse's trivial knowledge was put to the test with a series of questions only a true super-fan would know.

Saoirse's new movie 'Mary Queen of Scots' releases in Ireland on 18th January. Saoirse's co-star Margot Robbie also turned up to down some shots with Jimmy recently too.