"This follows an unacceptable start to the season with Steels bottom of the league with just two points from a possible twenty four," said the spokesman.
Chairman Alan Bethell paid tribute to the club's former manager. He said: "I would like to thank Chris for all his hard work over the last ten months and wish him all the best for the future."
Stocksbridge have moved quickly to replace Willcock after asking assistant-manager Darren Schofield to take over on a permanent basis.
The new manager leads the Steels to Matlock Town on Saturday with skipper Brett Lovell also named today as his player/assistant-manager.
Willcock first joined Stocksbridge in 2003 as a player and made over 200 appearances for the club in defense. He was named as assistant-manager in 2011 after a spell as caretaker.