'The Gypsy King', who was beaten for a second time by Usyk in December, had retired after beating Dillian Whyte in April 2022 but returned six months later.
"I'd like to announce my retirement from boxing," Fury revealed in a video on social media on Monday.
"It's been a blast. I have loved every single minute of it and I'm going to end with this - Dick Turpin wore a mask!"
Fury's exit from boxing sees him hang up the gloves with a professional record of 34 wins, two defeats and one draw in 37 fights.
The 36-year-old rose to stardom in 2015 with a famous heavyweight victory over Wladimir Klitschko, which ended the Ukrainian's reign of nearly 10 years.
Fury spent nearly three years away from the sport due to doping issues and subsequent battles with mental health, before returning in 2018.
He then took part in three bouts against Deontay Wilder - controversially drawing the first but winning the next two.
Fury's last win came against former UFC star Francis Ngannou, where he won by split decision in October 2023 despite surviving a knockdown.