He moves for an undisclosed fee, ending the Owls' long search for an extra striker.
"I am delighted to have secured a player of Jeffers' calibre," said Owls boss Brian Laws.
"He has spent most of his career in the Premier League because of the quality that he possesses, and I believe he can be a regular scorer with us in the Championship.
"We have been looking to secure a top quality striker over the summer and we certainly have that now."