The 25-year-old has joined the Black Cats for an undisclosed fee and has signed a four-year deal.
Turner, who joined Hull from Brentford for just £350,000 in July 2006, becomes Bruce's seventh summer signing after Darren Bent, Lee Cattermole, Fraizer Campbell, Lorik Cana, Paulo da Silva and loanee John Mensah.
A delighted Bruce said: "I believe that Michael is one of the country's premier central defenders.
"I have been looking to add size and strength to the back line and Michael fits the bill perfectly in that respect, as well as being an excellent technical footballer.
"His aerial ability provides us with another dimension at set-pieces at either end of the field, and I am delighted that he has chosen to buy into what we are trying to achieve here at Sunderland.
"He has developed immeasurably as a player whilst with Hull - I am extremely confident he will continue that progress with Sunderland and go on to be a big success."