The popstars are currently in Sydney for the glitzy event and Katy couldn't have looked happier as she spotted good friend Niall on the red carpet.
Niall, who arrived with his bandmates, was waiting for his turn to walk on the red carpet when Katy approached him for a catch up.
'Roar' singer Katy and Irish heartthrob Niall have previously flirted on Twitter, following a smooch on stage at the MTV Video Music Awards in 2012.
Then, in October last year, Niall jokingly proposed to Katy via Twitter after she called him "cute" following a guest performance on The X Factor.
Fast forward a month and Katy accepted Niall's 'proposal' in Tokyo, after hanging out with the band at a radio station.
Katy and Niall go way back to as far as 2010 - before he was even famous. Katy was in fact a guest judge on The X Factor during the arena auditions and she had the final vote of putting through Niall to bootcamp.
Niall later joined forces with Louis, Harry Styles, Zayn Malik and Liam Payne to form One Direction. The rest, as they say, is history!
Watch 1D's video for 'Night Changes' below: