[1] In 1875, the Diocese of Fond du Lac was created to serve the northeastern 26 counties of the state.

In 2021, it was announced that the diocese of Fond du Lac, Eau Claire, and Milwaukee would contemplate entering an agreement of greater collaboration.

[5] The merger agreement received approval at General Convention in June 2024.

Matthew A. Gunter (2024–Present) Nashotah House, in Nashotah, which is a seminary for the Episcopal Church, and St. John's Northwestern Military Academy in Delafield, Wisconsin, a private Episcopal military academy, are also located in the Diocese of Wisconsin.

Cadle Mission and Racine College were also located in the diocese.