• Sia on 'The Ellen Show'. (YouTube)Source: YouTube
Sia debuts the theme song from Disney Pixar's latest offering on 'The Ellen Show'.
Stephanie Marie Anderson

25 May 2016 - 11:34 AM  UPDATED 25 May 2016 - 11:42 AM

Adelaide-born pop star Sia stopped by The Ellen Show last week to perform her new single "Unforgettable".

The cover, which evokes a kind of underwater, old-school New York opulence, is also the theme tune from Finding Dory, the long-awaited sequel to 2003's Finding Nemo, in which Ellen DeGeneres voices the lead character, Dory.

"When I asked [Sia] to sing the theme song to Finding Dory I was thrilled when she said yes," Ellen said as she introduced her friend Sia.

"Dory's story, it makes me teary!" Sia exclaimed when Ellen thanked her for agreeing to sing the theme.

Finding Dory hits cinemas June 16.