In April, Rennie revealed he was learning to walk again after a rare condition had left him paralysed from the waist down.
The following month hundreds of people celebrated his inauguration as the new chancellor of Sheffield Hallam University.
He died from cancer before he could fully begin the role.
Vice-Chancellor Prof Liz Mossop said he had meant a huge amount to many different people.
“His upbringing, his tenacity and his resilience to achieve the amazing things he achieved were reflected in his career, but he also brought those skills and values to Sheffield,” Prof Mossop said.
“He supported so many different organisations and individuals across the city and in the region.
“He was always somebody who helped people, no matter who they were or where they came from. He just got out there and did the right thing for them.”