King joins the club under a cloud of controversy after vice-chairman Andy Scott stepped down following relegation from League Two.
Fans had expressed their desire for former striker Steve Burr to take-over before King penned a two-year deal.
"If I'm not good enough then I'll be gone, I know that," he told the Manchester Evening News.
"This is a new chapter for the club and I think my brand of football will improve the club.
"I play players that will excite, I've done that throughout my career and I back myself to bring exciting times to Macclesfield."