Councillor Alan Law has served Firth Park ward for a number of decades after being first elected in 1991 and kept his seat again at the local elections in May.
During his time on the council, he has served as Lord Mayor and as a senior member and former chair of the planning committee alongside other committee and community work.
Councillor Law said: “It has been a great honour and privilege to serve as a councillor for Firth Park for many years and I am really proud of the work we have done in the community. I would like to thank everyone who I have had the privilege of working with and particularly the local community in Firth Park ward.
“I still care passionately about serving the community and Sheffield, however, now is the right time for Firth Park to elect a new councillor and I wish whoever is luckily enough to be elected every success for the future, serving what is a brilliant community.”
Councillor Terry Fox, leader of the council, said: “I would like to thank Alan on behalf of the Labour group and the council as a whole for the contribution that Alan has made to the city and in particular his community of Firth Park over the years.
“Alan is widely respected by everyone and we are all grateful for the service and wish him all the best for the future.”
Councillor Law will step down immediately and an election for a new councillor in the ward will likely take place within a couple of months.