Tadeusz "Thaddeus" F. Zielinski (1916 – 11 Aug 1990) was a bishop of the Polish National Catholic Church (PNCC). Zielinski was born in Wilkes-Barre, Pennsylvania in 1916 to Francis and Mary Kompinski Zielinski. He was consecrated in Buffalo, New York on September 2, 1954^[1] and served as Prime Bishop of the Polish National Catholic Church from 1969^[2] until his retirement in 1978.^[3] Zielinski was the first American to serve as a bishop in the PNCC, and likewise, was the first bishop primate born in the United States. Zielinski died on August 11, 1990, at the age of 85 in Scranton, Pennsylvania.^[4] During his tenure, the use of the English language, in place of Polish, was popularized with the translation of liturgies and hymns.^[5]