The UK's Royal National Institute of the Blind (RNIB) will publish the braille version simultaneously with the other versions on 16 July 2005.
This will enable thousands of blind people to read the same book at the same time as their sighted peers. Prior to this, blind book fans have had to wait months or even years for the latest book to be "translated' into braille.
John Godber, RNIB's Head of Products and Publications, said: "The right to read is often denied to people just because they're blind. More than 95 percent of books are never published in a format that blind or partially sighted people can read such as braille, large print, or audio.
This is partly due to technology and most publishers not realising that blind and partially sighted people want to read books just the same as everybody else. Publishers as well as the government share a responsibility to make that happen."
JK Rowling said: "I'm delighted to be part of a publishing initiative that gives blind and partially sighted children and adults the same reading opportunities as sighted book lovers."
Ten-year-old Harry Potter fan Richard Wheatley, from Wandsworth in South London, lost his sight when he developed a brain tumour at the age of five.
Richard, whose favourite Potter characters are the Weasley twins, said: "I'm really excited that I'll be able to read 'Harry Potter and the Half-Blood Prince' by myself. Last time I had to get my Mum to read it to me and it took two months to finish. This time, I can get it as soon as my friends at school do and even read it in the car and in bed at night when I'm supposed to be asleep!"
Bloomsbury will also be publishing the large-print edition of 'Harry Potter and the Half-Blood Prince' on 16 July.
Sarah Odedina, Publishing Director of Bloomsbury Children’s Books, said: "We are delighted to be working with RNIB to ensure that all readers will be able to enjoy the braille, large print and standard print editions of 'Harry Potter and the Half-Blood Prince' on the same publication day."
Copies of 'Harry Potter and the Half-Blood Prince' in Grade 2 braille are available from RNIB.