Southside High School is a comprehensive public high school in Fort Smith, Arkansas, United States. Southside provides secondary education for students in grades 9 through 12 and is one of two public high schools in Fort Smith, the other being Northside High School, both of which are administered by the Fort Smith School District. The school is a three-time recipient of the National Blue Ribbon Schools Award of Excellence by the U.S. Department of Education (ED).