She said: ''I'm really excited to be going back to Belfast... you guys know how to have a good time! Woohoo!''
The event, which will take place on April 13, celebrates the opening of the Titanic Belfast visitor attraction, built on the grounds of the yard where the ship - which disastrously sank on its maiden voyage to America 100 years ago - was built.
It is rumoured Katy's performance will include a the world live premier of her track 'Anywhere in the World', which was created with Mark Ronson for the Olympics, and features samples of various athletes in training.
Olly Murs is also excited to be involved in the event, recently saying: ''I'll be bringing my nine piece band and hope to put on a great live show! I always love coming to Belfast and it will be a great way to commemorate 100 years since the Titanic was built there!''
Due to massive demand, a second batch of tickets will be available to fans from 9am tomorrow (05.04.12).