All 20 drivers appeared on stage in front of thousands of fans at Federation Square, after arriving by boat, as they previewed the new season and the campaign-opener.
Lewis Hamilton is aiming to close on Michael Schumacher's all-time record with a sixth world championship this season, and is preparing for his biggest challenge yet as Mercedes look to prolong their constructors' streak.
"It's going to be a long year," he said.
But the Englishman also had an ideal off-season, adding: "I'm really lucky. I got to do as many things as I wanted."
Mercedes team-mate Valtteri Bottas, meanwhile, is hoping for his "best year so far" in F1.
The team to beat for F1 2019? Quite possibly, judging by their superb testing. "Testing went very well," admitted new driver Charles Leclerc, Ferrari's youngest in almost 50 years. "It looks positive."
His team-mate Sebastian Vettel wants to join Hamilton on five titles this year.
"We had our weaknesses last year here and there and we obviously tried to fix those and do better this year," he claimed. "The spirit is right, the team is on track, and the car feels good so let's see how we start here."
Vettel also revealed the name for his SF90: Welcome to the grid, Lina.
Can Red Bull close in on Mercedes and Ferrari with their new Honda engines? Max Verstappen and new team-mate Pierre Gasly will certainly hope so.
"There's a big gap to make up to Mercedes and Ferrari," said team boss Christian Horner. "But we're confident we can do that over the course of the year."
"I'm stoked," said an enthusiastic Daniel Ricciardo as he greeted his home crowd following his move from Red Bull.
The Australian was joined by Nico Hulkenberg and team principal Cyril Abiteboul, who admitted Renault are looking to hone in on the so-called 'big three' in F1 2019.
"That's the target," he stated. "Its the reason I have these two guys around me. We want to keep the momentum going."
The American team were the big surprise at last year's Australian GP before not one but two pit-stop nightmares, and though they did not shine at winter testing, Haas boss Guenther Steiner said he was "cautiously optimistic".
"We don't know where we'll be yet," said Kevin Magnussen, who stood beside team-mate Romain Grosjean on stage.
Will McLaren start to make progress in their "long journey" back to the front of the grid this year? That's certainly the plan, with new drivers Carlos Sainz and British rookie Lando Norris at the helm.
"First thing we need to do is get to the midfield, then get to the front of the midfield," explained team chief Zak Brown. "I think we've got a great car, two great drivers and we've just got to keep pounding away"
"Expectations are very high," admitted Sergio Perez as the newly-named Racing Point drivers previewed the first race. "I think if we score good points on Sunday it will be a very good start for us."
Racing Point, formerly Force India, have a new driver in Lance Stroll and new investment to look forward to.
"Luckily we've got the funding behind us to bring upgrades to every race, including this one," added team boss Otmar Szafnauer.
Kimi Raikkonen had fun at the FIA Awards Ceremony last December...
Could Alfa Romeo be the surprise story in F1 2019? "After testing it looks like everybody is pretty close," said Kimi, who is partnered by Antonio Giovinazzi at Alfa. "But I don't think that's the end story."
Not all 20 drivers got to the Melbourne launch by boat... Daniil Kvyat was missing!
"I was with an Australian in the car and he got lost," said the Russian, who returns to the grid alongside rookie Alex Albon this year. Toro Rosso will be aiming for much better than ninth this year, with engine suppliers Honda thought to have made a step forward.
It could be a long year for Williams, but Robert Kubica, joined by rookie George Russell on stage, is just grateful to be back on the grid after nine years away.
"It's been a long journey," said the Pole. "I've had lots of years away from the sport but it's great to be back.
"In front of me will be a big challenge. I'm happy for the opportunity that Williams have given me."
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