Former DUP MLA Mervyn Storey has been co-opted by the party to fill their vacant seat on Causeway Coast and Glens Borough Council following the death of John Finlay.
Mr Storey, who lost his North Antrim seat in May's Assembly election, said it was a "daunting task" to succeed Mr Finlay as a councillor for Ballymoney.
The DUP representative died earlier this month following a cancer diagnosis. Mr Finlay revealed in June his illness was terminal but he sought to continue fulfilling his elected duties until his passing.
