The Jonas Brothers singer had been playing the role of Marius in musical Les Miserables at the Queen's Theatre in London's West End over the summer.
He ended the run by performing in the 25th anniversary of the musical alongside Matt Lucas at the O2 Arena on October 3.
His famous brothers Joe and Kevin had even flown over to see him perform for the final time.
Talking about the end of the show, Nick said: 'It is a bit emotional. I've met a lot of friends at the Queen's Theatre who are here tonight. I'm not sure when I'll see them next but it's a joyful goodbye, it's special we're here tonight and had this experience.'