The 66-year-old said his prison term had made him "feel happy that I have a good wife and a good family, that I can come home to a warm environment and a warm community".
"From that point of view, I felt lucky in some respects," he said.
He had served his sentence for contempt of court orders handed down by Judge Elizabeth Dunne in the High Court, which had been put in place to stop Quinn assets in the €500m International Property Group from being put beyond the reach of the Irish Bank Resolution Corporation (formerly Anglo Irish Bank).
His son, Sean Quinn Jr, also spent three months in jail last year for contempt of court after the Quinns' protracted legal battle with the former Anglo Irish Bank.
Speaking after his release from the prison's Training Unit yesterday, Mr Quinn said: "I suppose I found it tough when you come to 66 years of age, you've been through many a thing over that period.
"I could fit in with most environments and I fitted in. The staff were very good, very professional, but of course when you find a door slamming at nine o'clock at night, it's not nice. It's not something I was used to and it's not something I felt I deserved," he said.
Mr Quinn, who was met with a large sign erected on a northern-registered JCB welcoming him home, was filmed cradling his baby granddaughter Orna, who was Christened during his temporary release from jail over Christmas.
It is possible he could return to jail if the "charade" being pursued against his family in the courts continued, he said. "Can we go back to jail? Yes, we can," he said.
The businessman, who built a global business empire from humble beginnings on his family farm in Co Fermanagh, said in a BBC interview that he "wasn't always mad about the food" in Mountjoy prison and was glad to return home.
"I wouldn't call it frightening but it was certainly one that would make you think," Mr Quinn said.
He received a "very positive" response from other inmates in Mountjoy, he said.
"I think 100pc of them felt I shouldn't be there.
"I certainly felt I shouldn't be there, after creating 7,000 jobs, after never in my life owing anybody a penny."