The 16-year-old suspect was arrested near his home in Sydney on Sunday and appeared before a children's court on Monday.
He is accused of trying to obtain a gun, according to court documents.
Anzac Day commemorates Australians and New Zealanders who have lost their lives in wars and conflicts.
New South Wales state Police Commissioner Andrew Scipione said police believed the boy was acting alone.
He said: "We have taken swift action to ensure community safety on the eve of a sacred day on the Australian calendar.
"Our level of security at Anzac Day is always high, we have increased it. The attack didn't happen, so that's a good thing."
The campaign failed and 11,000 Anzac lives were lost.
On Monday, Prince Harry laid a wreath at Wellington Arch in London to mark the start of the commemorations in the UK.
He said: "When we reflect on Anzac Day we imagine the Gallipoli landings, what it must have been like, at dawn on the water, in sight of that rugged shoreline - and a collectively held breath, a leaden silence about to be broken.
"We consider the enthusiasm, the courage, and the heroism of the Anzac troops - ordinary men fighting for God, King and empire, for their mates, for adventure, for a world without war."
He then attended a 400-strong parade at the Cenotaph, where he laid a wreath on behalf of the Queen