The Rovers striker has joined the Owls for an undisclosed fee thought to be around £700,000 and has signed a threee year deal at Hillsborough.
"I am delighted, obviously. It's a massive football club and I think they are in the wrong division at the moment," Jeffers told the Owls official website.
"It's a chance for me to show people what I am all about. A lot of people have written me off but one thing I will do when I get regular games is score goals and I always have done that wherever I've been."