He took over on an interim basis when Craig Harrison left for Hartlepool on 26 May after guiding TNS to six consecutive Welsh titles.
Steve Evans, who has been assisting Ruscoe, will also be retained.
Both stepped up from coaching roles and led TNS in Champions League qualifiers against Europa of Gibraltar and Croatian side Rijeka in June and July.
The Saints kick-off their Welsh Premier season away to Bangor City on 11 August.
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Scott Ruscoe has been appointed manager of Welsh Premier champions The New Saints on a permanent basis.