Michael Heiss (April 12, 1818 – March 26, 1890) was a German-born American Catholic prelate who served as Archbishop of Milwaukee from 1881 to 1890.

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.

[2] Heiss then entered the University of Munich, where he originally studied law but switched to theology after deciding to join the priesthood.

[2][8] Pope Pius IX on March 3, 1868 erected the Diocese of La Crosse in Wisconsin and appointed Heiss as its first bishop.

After the conclusion of the conference, Heiss traveled to Bavaria to visit friends and family and to recruit more clergy for his diocese.

In 1871, at Heiss' request, the Franciscan Sisters of Perpetual Adoration transferred from Jefferson, Wisconsin to Milwaukee, where they built the St. Rose of Viterbo Convent.

[12][13] The sisters had previously worked with Heiss, managing the household responsibilities at Saint Francis de Sales Seminary.

He promoted the teaching of English in the parish schools and worked to recruit more American women into the religious orders.