The great-grandmother, who lives on the Isle of Wight, is the country's most senior supercentenarian, according to the Gerontology Research Group records.
Last year, she became the oldest person in the world to have a hip replacement, aged 112.
The former concert pianist, who lives at Highfield Nursing Home, said: "I don't feel very different to when I was 75."
She said she would be happy to celebrate with family and friends, a cup of tea and a slice of cake.
Her son Derek Hermiston, 85, said she had also told him she "wouldn't mind a nice new set of teeth".
As a young woman, he said she was "always the centre of parties".
"Now, we see her hands moving up and down and I think she dreams quite a lot of her piano days," the retired pilot said.
"I think she has melodies going through her head."
He added the family had recently been informed by Guinness World Records that she was the oldest person with a new hip, which he described as "quite a moment".
Born in Dulwich, south east London, on 18 January 1903 she was the oldest, and now the only surviving member, of six siblings - five girls and one boy.
She was brought up in Rottingdean, East Sussex, and went on to become a concert pianist before starting a car hire business in the 1920s.
Gladys Hooper's life
She later ran Kingscliff House School, which is now Brighton College.
After being widowed in 1988 she moved to Ryde on the Isle of Wight to live near her son.
Mr Hermiston also said his mother witnessed the shooting down of a German airship in 1916 by Lt William Leefe Robinson, who was awarded the Victoria Cross, and she is set to feature in a documentary being made by the pilot's great-nephew.
The UK's oldest person, Gladys Hooper, is celebrating her 113th birthday.