Askey, 26, was previously captain at Newcastle Town, making more than 300 appearances, having started his career at Macclesfield Town.
Manager Scott Dundas said: "James has played over 300 games at this level and is still only 26. He is a very good defender and will add experience to our young side."
Chasetown travel to leaders Atherton Collieries in the EVO-STIK League West Division this Saturday.
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