Wentzville Holt High School (Emil E. Holt Sr. High School, or simply Holt High School) is the oldest of the four high schools in the Wentzville R-IV School District and second oldest high school in St. Charles County, Missouri. With a 2020-21 enrollment of 1,934, Holt is the largest high school in St. Charles County. Although officially known as Emil E. Holt Senior High School since 1969, it was generally known only as Wentzville High School until 2000, when a renewed emphasis was placed on the "Holt" name in preparation for the addition of a second high school in the district.