The 23-year-old's future has been the subject of much debate since she claimed two bronze medals at the London Olympics last summer.
At a press conference today in London, the Mansfield-born swimmer confirmed she was bringing to an end a glittering career that has brought her Olympic, World, European and Commonwealth titles.
"I hate the word retire. I love swimming but as a competitive element and elite athlete I won't compete any more.
"I'll always be swimming even when I am 90 years old."
She said: "I hate the word retire.
"I love swimming but as a competitive element and elite athlete I won't compete any more.
"I'll always be swimming even when I am 90 years old."
She added: "I couldn't have done it without my family. Even my sisters, they helped me with my homework.
"Bill is the biggest thing....he has helped me as an athlete as much as a person. Now I've not got Bill without me, I feel a little bit lost.
"The medals - they are not just mine - they are my family's, Bill's. I think he is going to do such a brilliant job (as GB head coach)."
