The multi-media campaign is running across TV, radio, press, cinema and online across 22 countries.
The soundtrack to the TV ad is by Irish band Snow Patrol and is taken from the band's latest album, Fallen Empires.
Karen Buchanan, Publics London chief executive, said: "Ireland is a truly diverse country and a well-loved brand. With so much to drawn on, the task was to find a simple, compelling story for the country.
"In focusing on the uniquely immersive nature of a trip here, thanks to its welcoming people and stimulating experiences, we're confident we've found that."
Tourism Ireland will be hoping that the ad campaign will build on its social media activity from last year. Tourism Ireland now has 700,000 fans on Facebook.
Follow John Reynolds on Twitter @johnreynolds10