John was the Vikings' first ever manager following the clubs formation in 1997 and successfully managed the club for two and half years. He went on to take charge at Harrogate Town, Stalybridge Celtic and Buxton before returning for his second spell with the Vikings in July.
Club Secretary Andrew Morris says the hunt for a new manager is now underway and that the club hope to make an appointment this week ahead of their home game against New Mills on Saturday.
He said: "I can confirm that John left this morning and that we are now taking applications to replace him. The club would like to pay tribute to John for all his hard work and dedication and we wish him all the best for the future."
Chairman Des O’Hearne takes charge of team affairs until a new manager is in place after Reed's assistant manager Clive Freeman also left the club on Monday.