The annual Mayor Making ceremony will take place at Truro Methodist Church at 7pm on Monday.
Mayor Elect Cllr Mrs Carol Swain and Deputy Mayor Elect Cllr Sam Rabey will sign formal Declarations of Acceptance of Office.
The ceremony is traditionally attended by city and Cornwall councillors past and present, along with mayors and civic dignitaries from other Cornish towns.
Interim town clerk David Rodda, deputy town clerk Esther Greig, town crier Lionel Knight and the city’s macebearers will be present, as well as mayoral chaplain Rev Simon Clarke and Cadet Aidan Nelson.
The ceremony is open to the public; seats must be taken by 6.50pm.