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Oldest Private Schools in Washington

The average private school in Washington was founded around 1979 (2026-27).

The oldest private school in Washington is Desales Catholic High School and Assumption School, each founded in 1864.

Quick Facts (26-27)

# WA Schools Ranked: 587
Top 20 Range (Year Founded): 1864–1903
WA School Avg.: 1978
National School Avg.: 1968

Quick Facts (26-27)

# WA Schools Ranked: 587
Top 20 Range (Year Founded): 1864–1903
WA School Avg.: 1978
National School Avg.: 1968

Frequently Asked Questions

What is the Washington average private schools founding year?

The Washington average private schools founding year is 1979 for 2026-27.

What are the private schools with oldest founding year in Washington?

The top ranked private schools in Washington include Assumption School, Desales Catholic High School and St. Joseph Marquette Catholic School.

What is private high school and private elementary school with the oldest founding year in Washington?

The private high school with the oldest founding year in Washington is Desales Catholic High School, with a year of 1864. The private elementary school with the oldest founding year is Assumption School, with a year of 1864.

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