The Delphian School is a K-12 private school in unincorporated Yamhill County, Oregon, near Sheridan.  It is operated by Delphi Schools usingL. Ron Hubbard's study techniques as published by Heron Books. The Study Tech teaching methodology is licensed through the Scientology-related groupApplied Scholastics. The school building houses the offices of Delphi Schools and Heron Books.  Delphian is located in a rural area.
 
The grounds of the school were formerly a Jesuit novitiate,  and in 1976, The Delphian School was established at the site. Tuition at the school was $4,500 for boarding students and $2,800 for non-boarders in 1978. In the 1980s the campus was a candidate for the location of a federal prison, with the Federal Correctional Institution - Sheridan later built elsewhere in the Sheridan area.
 
The Delphian School in Oregon offers preschool, primary, and secondary education. The school is a boarding school and most students board, either full-time or five-day (going home for the weekends). The school also accepts day students; boarders must be at least eight years old, while day students can be as young as five. The main building on campus is a four-story, Art Deco style building with a brick exterior. Designed by Poole & Mcgonigle, it was built in 1933 for the Jesuit monastery.
Delphian School is a member of the Oregon Federation of Independent Schools and an Accredited Member of thePacific Northwest Association of Independent Schools