Mr Smith, who represented the Fairwater Ward for 34 years, stood down at the recent elections.
Torfaen CBC leader Bob Wellington said: 'Brian's long record as a politician shows how hugely popular he was. He will be missed by his many friends and family, and also the many people that he helped as a councillor over the years.'
Torfaen county borough solicitor Duncan Forbes said: 'He was a charming man who had a delightful sense of humour. Members of staff in the council will miss him greatly.'
A civic funeral will be held on Friday 30 July at 9.30am in St Gabriel's Church, Clomendy Road, Old Cwmbran, followed by cremation at the crematorium in Croesyceiliog, Cwmbran. Family flowers only. Donations can be made to the Active Support Unit, Velindre NHS Trust, Velindre Hospital, Velindre Road, Cardiff, CF14 2TL.