Northamptonshire County Council is saddened to announce the sudden death of Councillor Glenn Harwood MBE.
Cllr Harwood was elected to the county council in May this year, representing the Higham Ferrers division.
He was also deputy leader of East Northamptonshire District Council and served on Chelveston-cum-Caldecott Parish Council.
The flag outside One Angel Square has been lowered to half mast as a mark of respect.
County council leader Cllr Heather Smith said: "I am incredibly saddened by the unexpected passing of Cllr Harwood, a fantastic local councillor who was truly committed to representing the people of East Northamptonshire.
"He may have joined Northamptonshire County Council just a few months ago, but he made a real impact in that time and was a popular colleague and councillor.
"On behalf of everyone at the authority, I'd like to pass on my sincere condolences to his family at this difficult time."
Northamptonshire County Council chairman Cllr Dudley Hughes also paid tribute to his friend and colleague.
He said: "Since being elected to the county council, Cllr Harwood was a member of the Environment, Development and Transport Scrutiny Committee, contributing to scrutiny review work as well as work in the committee’s formal meetings.
"Cllr Harwood served in the Royal Signals, reaching the rank of Lieutenant Colonel, and served as Chairman of the Higham Ferrer’s Branch of the Royal British Legion.
"Always a gentleman, he showed wisdom and thoughtfulness in his contribution to the Council and will be sorely missed.
"On behalf of all members I send my sincere condolences to his family and friends."