Gennaro Maria Sarnelli was an Italian Roman Catholic priest and a professed member from the Redemptorists. Sarnelli was one of Alphonsus Maria de' Liguori's earliest companions and a prolific writer on a range of religious topics. He wanted to become a Jesuit though was dissuaded from this before working in the Hospital of the Incurables where his call to the priesthood blossomed. His apostolic zeal knew no limits: he preached missions and aided his friend Liguori in his work; he tended to the sick and helped to get girls out of prostitution despite the threats levelled against him.