The 59 year-old has agreed to join the Premier League club on a three-year deal to reunite with manager Manuel Pellegrini, having worked with the Chilean at Malaga.
"I am very excited. West Ham United is a club with huge ambition. The challenge to help deliver that ambition is what really attracted me to the role," Husillos told the club's website. "I know the manager well and know he wants to deliver an exciting brand of attacking football. It will be my job to supply him with the tools to do just that."
Malaga famously reached the quarter-finals of the UEFA Champions League in the 2012-2013 season under Pellegrini, with Husillos having overseen an expensive refit of the squad bankrolled by president Abdullah ben Nasser Al Thani.
However, the club has struggled to hit those heights in more recent years while under more stringent financial controls, and they were relegated from LaLiga this season.