The convicted sex attacker and former aviation boss arrived at the Four Courts complex this morning accompanied by a woman.
Lyons’ appearance comes following last week’s successful appeal by the Director of Public Prosecutions which said his sentence for the sexual assault of a young woman was too lenient.
Lyons was sentenced to six years by Judge Desmond Hogan in July 2012 for attacking the then 27-year-old woman in the early hours of the morning of October 3, 2010.
But the judge sparked outrage when he controversially suspended five-and-a-half years of the jail term and ordered him to pay his victim €75,000 in compensation.
Lyons was released from prison in December 2012 after serving his time, but the case was given a priority listing by the Court of Criminal Appeal last June.
Last week, at the Court of Criminal Appeal, Mr Justice John L Murray said that given the gravity of the offence, the mitigating factors could not justify the custodial part of the sentence.
Rhe case was listed for today when submissions will be made on an appropriate jail term.
Lyons was convicted by a jury last year after pleading not guilty at Dublin Circuit Criminal Court to the sexual assault.
He admitted the attack -- in which the victim was rugby tackled to the ground and violently physically and sexually assaulted.
But he claimed he was overcome with an "irresistible urge" due to a combination of alcohol, cholesterol medicine and cough syrup.
Defence barrister Patrick Gageby SC said Lyons was the most unlikely person to have committed an offence such as this.
"He was a man who had never been in trouble of any kind," he added."He was a man who was quite able to ask of gardai was there any suggestion of suspicion against him in relation to any other matter.
"He is a man who appears to have committed this criminal offence just touching on his 50th year: happily married, hard working and incredibly well thought of by all who knew him.
Mr Justice Murray told the barrister it had been a most disturbing offence for the victim.
"That it was his first offence or not did not make any difference to her in the end," he added.
Mr Gageby maintained Lyons could not submit a defence of involuntary intoxication without denying the charge, but claimed his client had offered to accept the victim's statement as evidence in court, sparing her taking the witness stand.
But counsel for the DPP, Caroline Biggs SC, told the appeal court the six-month custodial sentence did not reflect the gravity of the offence, the impact on the victim, or the impact on society.