The bankrupt businessman was back behind bars today after being given temporary release to spend Christmas with his family.
And he appeared to be growing increasingly comfortable with his situation as he strolled back into Mountjoy in a pair of runners.
Quinn had no baggage as he was dropped off at the gates in a BMW X5 driven by a relative.
The usually sharp-suited tycoon wore a maroon jumper, shirt and black slacks along with a pair of Asics runners.
He arrived back at the prison around 7.40pm last night -- just before the 8pm deadline set for his return.
The former billionaire is serving a nine-week sentence for contempt after allegations of a plan to put his family's €500m international property empire beyond the reach of the former Anglo Irish Bank.
He is due for full release on January 4.
His temporary release allowed him to spend Christmas Day at his palatial mansion in Ballyconnell, Co Cavan, and he was also able to attend the Christening of his granddaughter Orna, which took place on Wednesday.
The baptism is believed to have been called off twice as Quinn and his son Sean Jr served their prison sentences for contempt.
Fr Gerry Comiskey, who conducted the baptism ceremony, said: "When they (the Quinn family) heard of Sean's arrangements for when he got home, they didn't ask me about the Christening but I quickly volunteered to do anything that would accommodate them."
He said that Quinn was "not a bit worried" about returning to prison, adding "he knows it's almost over". Fr Comiskey also said that he had visited Quinn in prison, and that he collected a box with 800 cards and letters of support.
According to the priest: "Getting all the letters has strengthened his resolve."