The 76-year-old cleric, a top adviser to Pope Francis, was photographed at Sydney Airport early on Monday. He had arrived from the Vatican via Singapore.
Police have said the accusations relate to alleged "historical" incidents.
Cardinal Pell, who has strongly denied any wrongdoing, is due to face a Melbourne court on 26 July.
Australia's most senior Catholic figure was granted a leave of absence from the Vatican to fight the charges.
He did not make any comment on arrival in Sydney, local media said.
Victoria Police said the accusations arose from "multiple complainants".
Last month, Cardinal Pell told a news conference at the Holy See that he would travel to Australia if his doctors permitted it.
"I'm looking forward finally to having my day in court," he said.
"I am innocent of these charges, they are false. The whole idea of sexual abuse is abhorrent to me."
Cardinal Pell is considered the third-ranking official in the Holy See.
The Vatican treasurer, Cardinal George Pell, has returned to Australia as he prepares to defend himself against sexual assault charges.