The singer will voice Rapunzel in the film, and said that she considers it to be an honour, because she is such a huge fan of Disney.
Mandy, 26, started her career as a pop singer before turning to acting. She told Collider.com, 'I auditioned several times and then lucked out and got to be a part of it.
'But I remember getting word about the fact this film was happening and being the quintessentially girl fan of 'The Little Mermaid', 'Aladdin', 'The Lion King' and 'Beauty and the Beast'. Those were seminal movies of my childhood.
'So the prospect of joining that kind of legacy, that lineage of these Disney icons, was kind of overwhelming and a real honour.'