A 22-year-old man was arrested at the Sydney airport on Thursday as he was allegedly attempting to leave for Syria, the media reported.
New South Wales (NSW) Police said the arrest was was part of an ongoing investigation and there was no impending threat to the public, reports the BBC.
The police shared a picture on Twitter showing two plainclothes officers outside the terminal leading the man in handcuffs.
He was known to police for minor matters and had been under surveillance in the five months leading up to his arrest.
NSW Police Deputy Commissioner Dave Hudson said the man was expected to be charged with preparations for incursion into a foreign territory to commit acts of violence.
The charge carries a maximum penalty of life imprisonment.
"It appears he was radicalised online," Hudson said.
"We will allege that this 22-year-old man was going to leave Australia this morning in an attempt to get to Syria to fight for Islamic State(IS)."
It is a crime for Australian citizens to travel to parts of Syria.