Lourenço Eiró was born in Lisbon, Portugal in 1970. Having attended Jesuit High School in Lisbon he studied hotel management in Porto, joining the Society of Jesus at 23. After philosophy studies in Braga (Portugal), he spent Regency in a Jesuit school in Santo Tirso before going to Madrid, Spain, where he did studied Theology in Comillas University before going to Rome to study pedagogy in the Salesian Pontificial University. He then returned to work in Colegio das Caldinhas, Santo Tirso, as pastoral coordinator, teaching religion, organising pastoral activities such as reflection days, weekends and other pastoral events for students. He was also the catechetical coordinator of the school and coordinator of the Jesuit Camping association (Campinácios) while working for a masters degree in religious in the Catholic University of Oporto.