Dr Caroline Johnson said in a social media post: “I am incredibly saddened to learn of the death of Her Majesty The Queen.
"The Queen’s life has been a beacon of inspiration, devotion and stability for people in the United Kingdom and across the Commonwealth over her extraordinary reign.
“The people of Sleaford and North Hykeham will always be eternally grateful for her service.
“I send my sincere condolences to the Royal Family.”
She ended with the words: “God Save The King.”
Books of Condolence have been opened in St Denys’ Church, Sleaford and the people of Sleaford are already paying their respects, with a number of the town’s dress shops also placing mannequins in black clothes in the windows.
Lincolnshire Fire and Rescue Service has stated: “This is a sad day and Lincolnshire Fire and Rescue joins in the nation's mourning for Her Majesty The Queen who reigned for so long with dignity and respect.
“Our thoughts and condolences are with The Royal Family at this time.”
Kesteven and Sleaford High School and Carre’s Grammar School have both posted the same message: “Everyone at the school is saddened to hear of the death of Her Majesty, Queen Elizabeth II.
“Our thoughts and condolences are with the Royal family
“Our school will reflect over the coming days on her long and inspirational reign with affection and gratitude.”
William Alvey School in Sleaford added: “Very sad news about the Queen. An amazing lady. Our school will reflect this sadness in the coming days, in a way that we hope the children will understand.”