St. Charles East High School is a public four-year high school located in St. Charles, Illinois, a western suburb of Chicago, Illinois, in the United States. It is part of Community Unit School District 303. The school was known as "St. Charles High School" from its opening in 1977 until fall of 2000 when a second school in the city, Saint Charles North High School, was opened. At that time the school name changed to "St. Charles East High School."