Cotter, named for the diocese's first bishop, Bishop Joseph Bernard Cotter, was a boys school directed by the Christian Brothers of Saint John Baptist de La Salle.

The term "Cotter Family" refers to all the students, teachers, parents, administrators, alumni, volunteers and church members affiliated with the school.

Roughly 25-50%, depending on the year, of the student body are children of alumni, some third and fourth generations.

In 1993, local businessmen, headed by Bob Kierlin of Fastenal, started an endowment fund of several million dollars granting the school a technological make-over and allowing it to move to the Saint Teresa campus.

On July 1, 2021, Cotter Schools began offering educational opportunities for students from ages 16 months through 12th grade.