The Gypsy King returned to the Jessop Wing neonatal unit with his son, Prince, now aged 10, and his father, John, at the weekend.
He said: "It is truly amazing the work done by the team at Jessops, I would like to thank all of them for their hard work and dedication. I know first-hand how great they are for families."
Fury, whose wife, Paris, grew up in a traveller family in Doncaster, where the couple later married, was in the city to appear at the Sheffield City Hall on Sunday evening as part of a stage tour.
His son, Prince, was looked after on the unit during the first few weeks of his life.
The WBC heavyweight champion threw his support behind the Sheffield Hospitals Charity 21 Years of Jessops Appeal earlier this year and promised to visit the unit.
During the visit he met local artist, Lynn Hollingsworth, who, with help of funding from the charity, is transforming the Unit for families.
He took a tour with matron Claire Howard and chatted to families and staff.
He also video called neonatal ward clerk Holly Fearn, who is a huge fan but could not be at the hospital on the day of the visit.
Gareth Aston, chief executive of the Sheffield Hospitals Charity, said: "We were over the moon that Tyson could visit, staff and patients alike where overwhelmed by the visit. He spent so much time taking photos and chatting to everyone."
At the end of the visit Prince was given one of the charity's Jessop's Bears, offered to patients who have been cared for at the hospital.