The Italian takes the place of Paulo Alves, who spent just two months at the helm and left the club bottom of the Primeira Liga with just nine points from 14 fixtures.
Galderisi is a former Italy international who enjoyed playing stints with clubs including Juventus and Milan.
The 50-year-old has also coached extensively in his homeland, with his last job being a short-lived stint at hometown club Salernitana in 2012.
The coach is set to be unveiled, along with the rest of his staff, at Estadio Jose Arcanjo later on Tuesday.
Galderisi's first game in charge will be the visit of Vitoria Setubal on Sunday.
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