Peter H. Clark Montessori Junior High and High School, usually referred to as Clark Montessori, is a junior and senior high school in Cincinnati, Ohio, United States. Approximately 600 students attended the school in 2006. It is located in the Hyde Park-area woods, on the former estate of Ohio Governor Myers Y. Cooper (1929-1931), with trails in its "backyard". Recently completed in these woods is a small, ancient-Greek-style amphitheatre.

Clark is a public school, part of the Cincinnati Public Schools. Founded in 1994 as a seventh-grade extension of existing district Montessori elementary schools, Clark expanded with its first class to become a full junior and senior high school by the 1999-2000 school year, making it the first public Montessori high school in the United States.