The Sheffield fighter, now 36, held the IBF welterweight title between 2014 and 2017, but will perhaps best be remembered by British fans for finally facing, and beating, old foe Khan in February this year.
“I’ve had a long chat with my family and my parents, and it’s over for me. I’ll never box again,” Brook told the Sunday Telegraph.
“It’s a little emotional to be actually saying this out loud. I think everyone around me is pleased.
“Truth is, boxing is a very, very tough, dangerous sport, one in which you can be legally killed in the ring and I’ve finished now with all my faculties intact.”
Brook’s finest night came when he beat Shawn Porter to win the world title, though he emerged with credit when he was beaten by Gennady Golovkin, Errol Spence Jr and Terence Crawford.
Retirement looked an option on a number of occasions, but Brook’s resilience eventually led him to the Khan fight, which he won emphatically with a seventh-round knock-out, to end his career 40-3.
“I needed the Khan fight, I needed to settle the grudge, the feud. There is no dark feeling left in me now. I think when you have been in the ring with someone it passes, it leaves you,” added Brook.
“After that, I don’t think I needed to go on anymore. I’m one of the lucky boxers who has earned enough not to have to work, but I am going to give something back again, and I’d like to train or manage young fighters.
“I’d just like to be remembered as a fighter who would go in with anyone, feared no one and who gave the fans what they wanted.”