The former England international has got a £1m pay-off from Leeds and will now play for home-town club Hull for £2k a week on a one-year rolling contract.
Barmby said: "As far as I’m concerned, this shows the desire I have to play football. I know that has been questioned during the past two years. But if this doesn’t prove my motivation and passion for the game, nothing will.
"I am fiercely proud to finally get the chance to play for my home-town club and, hopefully, we will be successful together."