Francis Xavier Pierz (Slovene: Franc Pirc or Franc Pirec; German: Franz Pierz) (November 20, 1785 – January 22, 1880) was a Roman Catholic priest and missionary to the Ottawa and Ojibwe Indians in present-day Michigan, Ontario, and Minnesota. Because he attracted numerous Catholic German Americans to settle in Central Minnesota, he is referred to as the "Father of the Roman Catholic Diocese of Saint Cloud."
Father Pierz was born on November 20, 1785 to a peasant family in Godič, near the Carniolan town of Kamnik in the Austrian Empire (now Slovenia). He entered the seminary of Ljubljana in the fall of 1810 and was ordained on March 13, 1813 by Bishop Antonius Kautschitz. Two of his brothers also became priests.
After seven years as assistant pastor of the mountain parishes of Kranjska Gora and Fusine in Valromana, he was appointed parish priest of the villages of Peče and Podbrezje. After years of attempting to improve farming methods among the poor farmers of his parish, he published the book Kranjski Vertnar (The Carniolan Gardner) in 1830. His efforts led to his being awarded a medal of honor by the Carniolan Agricultural Society in 1842.