Orchard Lake St. Mary’s Preparatory has announced a new, innovative approach to learning and student development in the Fall of 2020. St. Mary’s will become the first Catholic high school in its region to operate under a co-divisional model, with boys and girls educated in a single-gender learning environment on the same campus.


  • Peace and Justice

  • What is Co-Divisional?

    This model offers a single-gender classroom experience alongside opportunities for boys and girls to engage socially, spiritually and in co-curricular activities. St. Mary’s prepares its students to excel in college and beyond by developing their abilities to think critically, work collaboratively, and succeed independently.


    In this culture, for the first time, both boys and girls will have all of the advantages of co-educational interaction without social pressures in the classroom. With the boys and girls in separate classrooms for the majority of their instruction, students have a choice of when and how they socialize during break times, before, and after the school day ends.


    Our mission and message remain the same:


    1. God

    2. Family

    3. St. Mary's


  • Welcome to St. Mary's


    St. Mary’s Preparatory sits on 115 acres of land located at Commerce and Orchard Lake Roads in Orchard Lake, Michigan. We are roughly 25 miles northwest of Detroit. Our Campus sits beautifully on 200 feet of shoreline on Orchard Lake. With immaculate views of Orchard Lake, we have 32 buildings on campus.

  • WE ARE


    A Catholic, college preparatory high school with a Polish-American heritage and legacy since 1885 A.D. We exist to provide deserving students with the moral guidance, discipline, and education to become Christ-like models of service and leadership for the world.



  • Girls Division

    Starting in the Fall semester of 2020, our historic institution will break new ground with the opening of the St. Mary's Preparatory Girls Division. This unique model will allow us to educate young women with the same Christ-like model that we have used use to educate young men for over 135 years.

  • Boys Division

    With 135 years of Catholic Education on our campus, St. Mary's Preparatory is one of the premiere Catholic boys educational institutions in the nation.

  • Latest News

    St. Mary's prep students lounge open now!

    Inspiring Words

    At today’s socially distanced class Mass, Father left the senior students with two thoughts: “1. God has great things planned for each of you. 2. You are stronger than you think you are.” His words resonated perfectly with the class of 2021.

    St. Mary's prep students lounge open now!

    Volleyball Team

    Congratulations to our Girls Volleyball team on their history-making win last night against Lake Shore High School!

    St. Mary's Preparatory
    Class of 2020 Graduation Mass​

    June 14, 2020

    Outdoor Mass begins at promptly 9:45 am
    This mass is limited to OLSM parents and students


    Class of 2020!

    CLASS OF 2020!

    Class of 2020! Mrs. Bartus, Mrs. Castiglione, Mr. Sheena, Coach Petry, and Mr. Rychcik lined campus down Commerce Rd with the 107 amazing faces of the class of 2020!

    St. Mary's prep students lounge open now!

    Prep Student Lounge Now Open

    Just a little peek at what the new student lounge looks like…

  • Hello & Welcome!

    Prep School Office: 248-836-1292

    School Fax: 248-683-1740

    St. Mary's Preparatory is located at
    3535 Commerce Rd.

    Orchard Lake, MI 48324

    Headmaster: Bob Pyles