Jan Maria Michał Kowalski

Maria Michał Kowalski
Archbishop
Church	Old Catholic Church of the Mariavites
In office	1909–1935
Successor	Maria Izabela Wiłucka-Kowalska
Other posts	29 December 1929 in Old Catholic Mariavite Church Continued in Catholic Mariavite Church
Orders
Consecration	5 October 1909 by Gerardus Gul
Personal details
Birth name	Jan Kowalski
Born	(1871-12-25)December 25, 1871 Latowicz, Vistula Land, Russian Empire
Died	May 18, 1942(1942-05-18) (aged 70) Hartheim Euthanasia Centre, Anschluss Austria
Buried	unknown
Denomination	Roman Catholic (1871–1906) Mariavite (1906–1942)
Spouse	Maria Izabela Wiłucka-Kowalska
Children	Michael
Sainthood
Venerated in	Catholic Mariavite Church
Canonized	1942 by popular acclaim
Shrines	Felicjanów, Płock County, Poland

Jan Maria Michał Kowalski (25 December 1871 – 18 May 1942) was a Polish priest, the first Minister General of the order of the Mariavites.

He came from a farming family in Latowicz, the son of John and Catherine Sitek Kowalski. He studied at the Warsaw seminary and was ordained a Roman Catholic priest on April 24, 1897 by Auxiliary Bishop of Mogilev, Francis Symon. Kowalski served in parishes in Lodz, Niesułków and Stara Sobotka. In 1900, he became a vicar at the Church of the Capuchins in Warsaw.

After a former seminary colleague introduced him to the Mariavite movement, he became a close collaborator of the foundress Feliksa Kozłowska.

At the time of his selection, he was the most important person in the Christian movement. He was consecrated bishop in 1909 by the Union of Utrecht of the Old Catholic Churches Gerardus Gul, archbishop of the Old Catholic Archdiocese of Utrecht. In 1919, the Mariavites officially changed their name to the Old Catholic Church of the Mariavites. Kowalski later called himself an archbishop.

Kowalski was killed, at 70, during World War II at the Nazi Hartheim Euthanasia Centre in Alkoven, Anschluss Austria. He was one of the victims of the Nazi war criminal Karl Brandt, who led the euthanasia Action 14f13.

Kowalski was deposed on 29 January 1935 by the General Chapter of the Old Catholic Mariavite Church in Płock; his successor in the Old Catholic Mariavite Church was Maria Filip Feldman ().