Holy Trinity School had its beginning in 1897 in a two-story frame store. The Benedictine Sisters taught in the school from 1897 to 1903, at which time the Adorers of the Blood of Christ began teaching in the school. In September of that year, there were just a few in the school, but by Christmas, 100 children were in attendance.

In 1902, because the daily trip by horse and buggy was not feasible, the farmers who lived west of Okarche, built a one-room school for their children to attend. This school, St. John’s, was affiliated with Holy Trinity and opened with 60 students.

In 1918, with the coming of the automobile, the St. John’s students began attending Holy Trinity. The increased enrollment of Holy Trinity necessitated erecting a new school in 1916. This building was used for elementary and high school until 1948, at which time a new high school was built. During the 1930s, Holy Trinity Grade School was listed in Superior Model Schools of the State, and the high school also rated high on the list of schools in
the state.

In 1968, the high school closed, and gradually the elementary school began using the high school building. The old structure was then used for religious education classes and parish meetings. In 1997, the old school was razed to make room for the present parish hall. At the same time, a four-room addition was built onto the present structure for more classrooms to create the school as we know it today.