Spellman, 19, is a defender or defensive midfielder, and was previously on the books of Tranmere Rovers where he signed professional forms on completing his scholarship.
He made three first-team appearances for the Prenton Park outfit, having played for them at Under-18s level.
The club also announced the signing of Alex Downes from Colwyn Bay.
Downes, 20, is a graduate of the Chester Academy, and already has experience of Northern Premier League football through loan spells at Ramsbottom United as well as the Bay, who are now members of JD Cymru North.
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