Lisowski opens his title defence in Belfast against China's Huang Jiahao, ranked 108th in the world. Their match is scheduled for Sunday afternoon at the Waterfront Hall.
The BetVictor Northern Ireland Open runs from October 18 to 25 as part of the Home Nations series. Tickets start at £16.50. The total prize fund is £550,400, with £100,000 for the winner.
In last year's final, Lisowski beat close friend Judd Trump 9-8 to claim the first ranking title of his professional career. Reaching the Welsh Open final later earned him the £150,000 BetVictor Home Nations bonus.
This season has been tougher. Lisowski has reached one ranking quarter-final and suffered several early exits. He was ranked 18th in the world ahead of the Belfast defence.
"It has been very frustrating so far," he said. Lisowski had known for months that he would probably be unavailable in January and February, and tried to make progress before then. "I just need to work hard to get myself out of the little rut I am in." Seven-time world champion Stephen Hendry said Lisowski needed to find a spark as he prepared to defend the title.
Then comes the break. Lisowski expects to miss one or two tournaments so he can be with his fiancée, Bela Nogueira, for the birth of their son in Rio de Janeiro in January 2027. "I'm going to be there for the birth, obviously. I can't miss that," he said. "If it means missing a few snooker tournaments, so be it."
The couple are preparing a nursery. Lisowski joked that "Little Pele" is on the way as he gets ready for fatherhood.
His father died in March 2025. At the gender reveal, a dog brought blue balloons to announce they were having a boy. "I remember I really wanted it to be a boy," Lisowski said. "When the dog came around with the blue balloons, I couldn't believe it. I was so happy."
Lisowski said he had been thinking about his father and the chance to pass on what he had learned as a son. "Maybe I'll get to relive what he did with me. I can try to emulate that." He called the prospect "very special and very emotional" and described the coming change as "a good distraction" during the season.
After beating Trump in the Belfast final, Lisowski recalled feeling light-headed, as though he were dreaming.
