Since few studies exist that examine the relationships between adolescent obesity and academic performance, the purpose of this study was to examine the impact of obesity on high school students’ academic performance in a low socioeconomic school district. The topics addressed in this study included prevalence of overweight and obesity in high school students and the impact of overweight and obesity on student academic performance. The potential population of this study consisted of 236 high school students aged 14 to 19 years old enrolled in a rural Mississippi school district in grades 9 -12. However, only 35 students had usable data in all of the categories that were examined, and, therefore, were used as the population for the final analysis. The participants studied in this study consisted of all students assigned to one physical education teacher. Each student was administered the Project Health Student Measurement Chart which was developed by Project Health, a research entity of the Institute of Epidemiology, Jackson State University, Jackson, Mississippi. The Project Health Student Measurement Chart was utilized to enable the participating students to be examined on characteristics that included Body Mass Index (BMI), blood pressure and pulse rate. Student information collected on their obesity status based on BMI level was also collected in this study. In addition, the students’ performances on subject area tests and/or end-of-course assessments in the academic areas of Algebra I, English II, Biology I, and U.S. History from 1877 were accessed from the school’s records. Based on the results of this study, 48.60% of the students in the Canton Public School District are overweight/obese. However, the findings of this study revealed that there was no significant difference between overweight/obese and non-obese students’ academic performance on subject area tests and/or end-of-course test by age, gender and grade, and no significant relationships in the academic performance of overweight/obese and non-obese students on end-of-course test scores for 10th – 12th grades, as measured by Algebra I, English II, Biology I, and US History from 1877.