Hii was born to a Chinese-Malaysian father and an English mother. He attended the Queensland University of Technology. His early theatre work was with The Emerge Project an arm of Switchboard Arts. There he performed in a number of original productions in Brisbane by local playwrights between 2005 and 2007. From 2009 to 2011 he attended the National Institute of Dramatic Art (NIDA) in Sydney where he graduated in 2011. During his time at NIDA he played in the Sydney indie-rock group Rapids alongside fellow actors Angus McLaren and Jamie Timony.
On 12 June 2013, Hii joined the cast of Neighbours as Hudson Walsh. Hudson was introduced as a love interest for established character Chris Pappas (James Mason). On 20 June, Hii told Daniel Kilkelly from Digital Spy that he had been asked back to continue filming the following month. After leaving Neighbours, Hii was cast as Prince Jingim in the Netflix drama Marco Polo. He will be portraying Alistair Cheng in the movie Crazy Rich Asians based of the novel of the same name by Kevin Kwan.
