At an airport hangar in the city of Melbourne, the president said: "I'm here because I want to be among my friends and among the people"
He was introduced by his wife, First Lady Melania Trump, who led the crowd in prayer and said he was "creating a country of great safety and prosperity".
At an airport hangar in the city of Melbourne, the president said: "I'm here because I want to be among my friends and among the people.
"This was a great movement - a movement that has never been seen before in our country or probably anywhere else."
Mr Trump told his audience that they were part of a movement "sweeping the world", adding: "Look at Brexit."
He said he wanted to address the crowd "without the filter of fake news" - and insisted the "dishonest media" is part of a "corrupt system".
To cheers from the crowd, Mr Trump warned: "They have their own agenda and their agenda is not your agenda."
The words came just days after his last attack on the media, in which he said "the level of dishonesty is out of control".
Mr Trump's presidency has lurched from crisis to crisis since his inauguration, including the botched roll-out of his immigration order, struggles to confirm his cabinet picks, and a succession of reports about strife within his administration.
But Mr Trump told his audience that "making America great again" is a campaign and "it's not easy, especially when we're also fighting the press and the media".
He then moved on to trade, saying "every country over a long period of time has been taking advantage of the stupidity of our politicians and it is not going to happen any longer".
Companies planning to move jobs overseas were also threatened, with Mr Trump warning they will pay a "very, very big price".
He added: "Jobs are starting to pour back in... like you've never seen."
Mr Trump went on to say that he had saved the day for American business with a fighter jet deal, as well as a deal to build the pipes in the Dakota Access Pipeline project.
He returned to familiar phrases used throughout his successful campaign during the 45-minute speech, including "Drain the swamp", "We don't win anymore" and "Make America great again".
A surprise came about half way through the event, when Mr Trump invited a man in the audience to join him on stage.
The supporter, who was wearing a T-shirt adorned with a picture of Mr Trump, said he had been waiting since 4am to hear the president speak at the rally.
"When President Trump during the election promised all these things that he was going to do for us, I knew he was going to do this for us," the voter told the crowds.
Mr Trump later re-appeared at the podium, admitting: "I wouldn't say the Secret Service was thrilled with that but we know our people - we know our people."
The wall being planned between the US and Mexico also got a mention, with Mr Trump saying "construction on the great border wall will start very shortly".
Mr Trump then hit out at the judges who have put on hold his travel ban, which halted travel to the US for citizens of Iran, Somalia, Iraq, Libya, Sudan, Syria and Yemen.
The order was blocked by a US federal court, but Mr Trump has said he will order a new ban to be put in place.
He told the crowd: "We will be doing something over the next couple of days... we won't give up, we never give up."
(Additional reporting from IRN)