Giovanni Maria Mastai-Ferretti was an Italian prelate, known for his election as Pope Pius IX in 1846. If you are looking for synonyms for Giovanni Maria Mastai-Ferretti, you may refer to him as Pope Pius IX, or simply Pius IX. Other terms that may be used to refer to him include Roman Catholic Church leader, Bishop of Rome, and Holy Father. These terms all refer to the same person, but they are different ways of describing his role and position within the Catholic Church. Regardless of the term used, Giovanni Maria Mastai-Ferretti remains one of the most influential and well-known popes in Catholic history.