The Ukrainian Catholic Eparchy of Saint Nicholas of Chicago is a Ukrainian Greek Catholic Church ecclesiastical territory or eparchy of the Catholic Church in the whole Western United States and Midwest (except Ohio), Alaska, and Hawaii.

As of 2020[update], the St. Nicholas Eparchy has 43 churches and missions in the western USA.

The bishop of the eparchy is Venedykt Aleksiychuk as of April 20, 2017[update].

St. Nicholas Ukrainian Catholic Cathedral is the mother church of the eparchy.

[1] The eparchy governs parishes, which are located in the following states: