Big Sam joins the club on a two-year deal with the remit of gaining promotion back to the Premier League within two seasons although, preferably one.
His contract is believed to be worth £1.25 million per year with a £1 million bonus for gaining promotion.
The former Bolton and Newcastle manager has been out of work since being removed from his position at Blackburn Rovers half way through last season following their takeover by Indian chicken farmers.
His managerial record speaks for itself, having established Bolton as a Premier League club and guided them to four top-eight finishes, cup finals and European football.