The 27-time Primeira Liga champions have been without a permanent manager since parting company with Paulo Fonseca in March.
Luis Castro took interim charge following Fonseca's departure, with Porto having since conceded their title to Benfica.
Porto also fell to Jorge Jesus' side in the Taca de Portugal and Taca da Liga recently, with their final league game coming against the newly crowned champions on Sunday.
Since retiring from a playing career that saw him feature for Real Madrid, Barcelona and Rayo Vallecano, Lopetegui has managed at Rayo as well as taking charge of Spain at Under-19, Under-20 and Under-21 level.
Having won the Under-19 and Under-21 European Championships with his country, Lopetegui will be tasked with ensuring THAT the Primeira Liga title returns to Estadio do Dragao next season.
In what will be only his third club role, Lopetegui will take charge of a side that will finish this season third - in the final UEFA Champions League spot.
