The BBC chat show host was a student at the school, finishing his studies in 1981.
He will return to officially launch Bandon Grammar School — A History, written by principal Ian Coombes.
Mr Coombes has been principal for the past 23 years and the idea to write a history of the school came about when he was studying for a masters degree.
“I realised there hadn’t ever been a history of the school published before, so I decided I wanted to document it in a book,” Mr Coombes told The Echo.
The book, which took around three years to complete, required extensive research and Mr Coombes consulted school records, old editions of the school’s magazine, Irish Examiner records, the Cork Constitution, as well as memorabilia from past pupils in creating the book which details the school’s 378-year history.
The official launch takes place on Monday November 25.