Other members of Willcock's backroom team, including his assistant Lincoln Adams, have also left the club.
Willcock arrived at Bower Fold in May 2022 but endured a difficult season as the club were relegated from the Northern Premier League.
Their return to Step 4 was confirmed as Celtic won just one of their final 16 league matches under Willcock.
Following their relegation, Willock penned an open letter to supporters, where he admitted that they were "at a crossroads in the history of the football club" and needed to use the setback £as a catalyst for positive change and channel our energy towards creating a brighter future".
The search for Willcock's successor is expected to begin imminently.
Photo credit: Stalybridge Celtic
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