|The Most Reverend|
|Archbishop of Milwaukee|
|Installed||September 7, 1881|
|Term ended||March 26, 1890|
Bishop of La Crosse (1868-80)|
Coadjutor Archbishop of Milwaukee (1880-81)
|Ordination||October 18, 1840|
|Consecration||September 6, 1868|
April 12, 1818|
Pfahldorf, Bavaria, Germany
March 26, 1890 (aged 71)|
La Crosse, Wisconsin
Michael Heiss (April 12, 1818 - March 26, 1890) was a German-born prelate of the Roman Catholic Church who served as the first Bishop of the Diocese of La Crosse (1868-80) and the second Archbishop of the Archdiocese of Milwaukee (1881-90).
Michael Heiss was born in Pfahldorf, Bavaria (part of present-day Kipfenberg), to Joseph and Gertrude (née Frei) Heiss. He received Confirmation when he was only two years old because his parents feared they would be without a bishop for a prolonged period of time due to tension between church and state. He entered a Latin school at age 9, and later graduated from the gymnasium of Neuburg in 1835.
Heiss then entered the University of Munich, where he originally studied law but switched to theology after deciding to join the priesthood. He completed his studies at the ecclesiastical seminary in Eichstätt.
He was ordained a priest by Bishop Karl-August von Reisach on October 18, 1840. Because, at age 22, he was younger than the age requirement for ordination, he was granted a dispensation by Pope Gregory XVI.
Heiss served as a curate in Raitenbuch and afterwards in Pleinfeld. In December 1842, he immigrated to the United States, where he became pastor of Mother of God Church in Covington, Kentucky. He remained in Covington until 1844, when he was made secretary to John Henni, the newly appointed Archbishop of Milwaukee, Wisconsin. He erected St. Mary's Church in Milwaukee, and served as its first pastor with his charge extending over an area of 52 square miles. In 1856, he was named the first rector of St. Francis Seminary, serving for 12 years.
This section needs expansion with: additional facts of Bishop Heiss's activities for the Diocese of La Crosse 1868–1880. You can help by adding to it. (October 2014)
Heiss was appointed Bishop of the Diocese of La Crosse on March 3, 1868, and was ordained a bishop on September 6, 1868.
On March 14, 1880, Bishop Heiss was appointed coadjutor Archbishop of Milwaukee. On September 7, 1881, he succeeded Archbishop John Henni on his death as Archbishop of the Archdiocese of Milwaukee. He was an opponent of the Americanist heresy.