She now faces up to five years in jail, with pressure expected to mount on Justice Minister Alan Shatter to seek her impeachment.
The 60-year-old judge was ordered to hand in her passport to Malahide Garda Station yesterday as she awaits next Thursday's sentencing hearing.
The District Court judge was convicted of attempting to deceive Thomas Davis out of half of his estate while he was a client of her solicitor's firm.
Her trial heard she tricked the elderly man into bequeathing half his estate, worth about €1m, to her own two children.
Perrin ran a solicitor's practice in Fairview in Dublin before being appointed a District Court judge in February 2009, a month after she carried out the scam.
The jury returned a guilty verdict yesterday and Perrin was remanded for sentencing.
If she does not appeal her conviction or resign, she could trigger the first ever successful impeachment of an Irish judge.
A judge can only be removed by a joint resolution adopted by both houses of the Oireachtas for "stated misbehaviour or incapacity".
Perrin has been a leading light in the Christian Girls' Brigade and a respected member of the Anglican parishes of Malahide and Portmarnock.
She appeared shocked at the verdict. She wiped away tears and was comforted by her husband Albert and supporters.
Perrin, of Lambay Court, Malahide, pleaded not guilty at Dublin Circuit Criminal Court to deceptively inducing Thomas Davis to bequeath half of his estate to Sybil and Adam Perrin at her office on Fairview Strand on January 22, 2009.
According to the prosecuting counsel Dominic McGinn, Perrin fought the case using "lies, half-truths and deceptions". When the scam first came to light she claimed it was a mistake by her secretary but later claimed she had drafted the will in line with Mr Davis's instructions.
Her defence team suggested that Mr Davis, who is in his eighties, suffered memory problems and had forgotten leaving half his estate to the Perrin children. The prosecution produced medical evidence that Mr Davis had no memory problems.
Charges of deception relating to the will of Mr Davis's wife, Ada, were dropped before the trial because her mental state has declined to the point where she is unable to give evidence.
The trial heard Thomas and Ada Davis decided to make their wills with Perrin before she was officially made a judge.
Mr Davis gave instructions to leave €2,000 each to various churches, €2,000 each to Perrin's children and split everything else between his two nieces.