Adelaide Archbishop Philip Wilson has been found guilty of concealing child sex abuse during the 1970s in the NSW Hunter region.
Magistrate Robert Stone handed down the verdict in Newcastle Local Court on Tuesday following a magistrate-only trial.
The 67-year-old clergyman is the most senior Catholic official in the world to be charged and convicted of the offence. He faces a maximum two years in prison.
Wilson was accused of covering up the abuse of four boys by pedophile priest James Fletcher during the 1970s.
He has been diagnosed with the early stages of Alzheimer's disease and claimed to have no memory of a 1976 conversation he had with Peter Creigh, one of the alleged victims.
The defence tried to have the case thrown out and argued Wilson was not guilty because there's no evidence to prove the archbishop was told about the abuse, believed it was true or remembered being told about it.
He is the most senior catholic official in the world to be convicted of concealing child sex abuse.