WATCH: Carlow native Saoirse Ronan explains pub lock-ins to US chat show host Jimmy Fallon

Carlow native Saoirse Ronan has been telling American chat show host Jimmy Fallon about lock-ins and even enjoyed a pint of Guinness with him on this week’s episode of The Tonight Show.

The actress showed people exactly how to do enjoy a lock-in and sang the iconic Christmas song "Fairytale of New York" at the top of her voice.

The pair channelled a "good ol' fashioned Irish pub lock-in’" which according to the Carlow woman, is when “the whole town just goes to the pub, we lock the doors, we have a drink and we have a singalong”.

Here’s how it went: