Rice, who won BBC One's singing competition All Together Now's £50,000 prize a year ago, added that his track "might just be a ballad but that song's got a big message and I can't wait to perform it and show the rest of the world what this song's all about".
Kate Miller-Heidke performs Zero Gravity on Saturday. I just thought it would be great experience.
Miller-Heidke said she will be thinking about the Eurovision message of inclusivity when she takes to the world stage.
Electric Fields took out second place with their song 2000 and Whatever being awarded 114 points overall, while Sheppard came in third place with On My Way on 87 points.
"It means true inclusivity and diversity; and it means breaking down of genres and anything goes".
"What an fantastic performance".
Miller-Heidke performed her song Zero Gravity alongside some of Australia's biggest artists and the scores of the viewing public and jury were combined for the official results.
"It's a standout song with mesmerising staging. All of us here at SBS are so thrilled that the whole country has embraced this truly diverse and inclusive show and I know that Eurovision fans will adore Kate as much as we do when we get to Tel Aviv in May!"
Eurovision: You Decide is back for 2019 with a brand new format!
Kate is perhaps best known for her 2008 song "Caught In The Crowd" and was one of the more well-known faces taking part in the decider this year.
Queensland Tourism Industry Development Minister Kate Jones said Kate will be getting a proud send-off.
Eurovision - Australia Decides creative director of Paul Clarke said: "It's a win for out of the box brilliance, which Eurovision devours".
BDS Australia also staged protests outside and inside the Gold Coast event on Saturday night.
Dami Im, who charged to a #2 finish at the 2016 contest, capped the show off with a solo piano performance of Sound Of Silence moments before the final announcement.