Other acts in the running included much-loved indie pop band Sheppard, modern electric-soul duo Electric Fields, legendary drag queen and reality television veteran Courtney Act, pop-opera star Mark Vincent, 16-year-old singer-songwriter Leea Nanos, rock music icon Ella Hooper, Tania Doko, The Voice victor Alfie Arcuri and Aydan.
The blonde beat out electronic duo Electric Field, who placed as runner-up during the live decider.
The lyrics to her song detail her struggle with post-natal depression and the feeling of weightlessness as she recovered.
Michael Rice has won the public vote to fly the flag for Great Britain at this year's Eurovision Song Contest in Tel Aviv.
Miller-Heidke said she will be thinking about the Eurovision message of inclusivity when she takes to the world stage. Kate is a total original and Eurovision will love her. Electric Fields delivered a stellar performance, and came so close, but it was Kate's night.
Isaiah came ninth in 2017 with Don't Come Easy, but Jessica Mauboy only managed 20th place with We Got Love past year.
"Having a child shakes your world".
Eurovision: You Decide is back for 2019 with a brand new format! "So it's about that sense of becoming myself again".
Cardiff lead Premier League tributes to Sala
It was this search that resulted in Sala's body being found on 4 February, however, Ibbotson's body is yet to be discovered. Earlier today, the club registered a 2-1 win as Kenneth Zohore scored a dramatic injury-time victor against Southampton .
Eurovision 2019 will be held in Tel Aviv on May 18.
In 2018, Israeli singer Netta Barzilai won the contest, helping to bring the competition to her country this year.
It will be the 64th edition of the Eurovision Song Contest.
The campaign urges artists, musicians and other cultural institutions not to tour to Israel while it "maintains a regime of settler colonialism, apartheid and occupation over the Palestinian people".
BDS Australia also staged protests outside and inside the Gold Coast event on Saturday night.
Kate Miller-Heidke celebrates winning the 2019 Eurovision - Australia Decides final.