Blake, who becomes Rovers' second signing of the day after Welsh winger David Cotterill, is hoping to guide the club back to the Championship at the first time of asking having dropped out of the second tier last term.
"I'm really looking forward to the challenge that lies ahead and I can't wait for the season to get started," he told Doncaster's official website.
"With Dean (Saunders, manager) being here, it adds that little bit extra for me having played with him at Bradford.
"Obviously as a player you want to play at the highest level, but I've done that, now I'm ready for a different sort of challenge at Doncaster. I spoke to the gaffer about the players already here and I think we have enough quality to bounce straight back."