McHenry High School (MCHS) is a four-year public high school located in McHenry, Illinois, a northwestern suburb of Chicago, Illinois. It is part of McHenry Community High School District 156, which operates two separate campuses, named The Upper and The Freshman Campus. The Freshman Campus opened in 1925 and currently enrolls 9th-grade students. The Upper Campus opened in 1968 and enrolls 10th-grade through 12th-grade students. The high school serves students in the communities of McHenry, Wonder Lake, Bull Valley, Holiday Hills, McCullom Lake, and Lakemoor. The current principal for both campuses in McHenry High School is Dr. Jeff Prickett, Ed.D since 2021. The school's colors are orange and black. The school's mascot is a Warrior, and it is named Leonidas the Warrior.