Flags have been lowered to half mast as Southland marks the overnight passing of New Zealand's head of state, Queen Elizabeth II.

Southland's mayors have paid tribute to the late Queen, as well as inviting floral tributes, the signing of condolence books and making plans for remembrance services.

Invercargill City (ICC) Mayor Tim Shadbolt said it had been with great sadness that he had received the news this morning (9 Sept) of Her Majesty's passing.

“Her visit to Invercargill in 1954 was an absolute thrill for the people of this city. There was true, deep affection held in Aotearoa for Her Majesty and she will be truly mourned by millions around the world," Mayor Shadbolt said.

“She was a woman of great mana who dedicated her life to the service of her people.”

Southland District (SDC) Mayor Gary Tong said that it was with great sadness that Southland and New Zealand awoke this morning to learn of the passing of Her Majesty Queen Elizabeth II. 

"She was a revered monarch, much loved and respected not just throughout the Commonwealth, but around the world, during her extraordinary reign of 70 years", he said.

"She will be remembered for her dignity, wisdom and unwavering sense of duty to her subjects."

"Our thoughts are with King Charles III and the Royal family as they mourn the passing of a cherished sovereign."

Gore District (GDC) Mayor Tracy Hicks also offered his sincere sympathy and respect to the Royal Family on Queen Elizabeth II passing.

"She has been a tower of strength in an ever-transforming world. She was one of the few constants we, as a nation and as individuals, have known," Mayor Hicks said.

"She was always a friend of New Zealand. All who had the pleasure of meeting her speak glowingly of her knowledge and respect for our place."

"We wish the heir to the throne and her successor King Charles III all the best for his reign. May God bless him and give him wisdom in all he does", he said.

Environment Southland chairman Nicol Horrell said the queen was well-known for her wisdom, warmth and grace.

"I was born the year of the Queen’s coronation, so she has always been there in my life," Horrell said.

"I know many Southlanders will be feeling her loss and that some of you will have had personal encounters with her, too."

She has been a beacon of stability in a rapidly changing world and her unwavering service to Britain, the Commonwealth, and indeed, the world was a model for us all, he said.

People are invited to lay floral tributes at Feldwick Gates in Queens Park or at the Town Hall in Bluff.

Condolence books will be available to sign at Invercargill City Council's Administration Building, Invercargill Public Library, Bluff Service Centre, Gore District Council's main office and Gore and Mataura libraries.

Sheets will be available at all SDC offices and libraries for people to leave their personal messages of condolence. These will collated and bound in due course.