"I HAVE SOME VERY EXCITING NEWS TO SHARE!," she wrote on Instagram. "In 2018, I will be representing Australia at the 2018 Eurovision Song Contest! I will sing my heart out for Australia, I'm so proud to be officially representing my country and a little bit nervous - mainly about the stress of the dress! Let's go Aussies!"
It's not the first time the 'Fallin'' songstress has been involved with Eurovision. Her special halftime performance four years ago (she crooned to 'Sea of Flags') in Copenhagen was what scored Australia an entry spot into the European competition.
Talking to The Daily Telegraph, The Secret Daughter star said she has "unfinished business" with Eurovision.
"Hell yeah, I was jealous," she said about seeing her comrades sing on stage over the years.
"Of course I was rooting for them and they all did so great. But I wanted to be on that stage; I wondered if I could crash it."
So, what will Jess sing as her entry song? Well, it's something she'll co-write.
"Portugal is a country that has a rhythm; even when they speak, it sounds like they are singing," she said.
"It is such an opportunity to put all of my heart into creating something that will rock the world."
Eurovision is the world's biggest song contest and chose to include Australia in its annual event three years ago. Guy Sebastian, Dami Im and Isaiah Firebrace have flown the flag for Oz in the past.
Guy came fifth in 2015, Dami came second in 2016 (Australia's closest shot to winning the title), and Isaiah came ninth overall this year.
The Eurovision contest will be held on May 9 to 13, 2018, in Lisbon, Portugal. Myf Warhurst and Joel Creasey will be hosting the SBS broadcast of the show.