John Marshall High School is a public high school in Oklahoma City, Oklahoma. The original location of John Marshall High School opened in 1950 at 9017 N University Ave., Oklahoma City, Oklahoma. The new location of the school opened in 2005 at 12201 North Portland Avenue, Oklahoma City, Oklahoma. The school is named in honor of the 4th Chief Justice of the United States (1755–1835), John Marshall. John Marshall was the longest working Chief Justice in Supreme Court history.