John Paul Nazarius or Giovanni Paolo Nazari (December 1556 – 14 February 1645)[1] was an Italian Dominican theologian.
He entered the order at an early age in his native town and from the beginning was noted for his spirituality and love of study.
In 1592 he was sent by Pope Clement VIII and the General of the Dominicans, Ippolito Maria Beccaria, to accompany the Apostolic Nuncio to Prague to combat the prevailing heresies.
There he spent three years teaching in the Studium Generale of the province, lecturing on theology in the university, preaching and defending Catholicism against the innovators.
In 1597 the pope appointed him to defend in a public disputation at Chiavenna the Catholic doctrine of the Holy Sacrifice of the Mass against Calvinistic preachers.