With growth in STEM postsecondary programs and careers positioned as a national priority, ensuring that K-12 science classrooms are staffed with highly qualified teachers is an important step towards building student interest in STEM and preparing students for STEM careers. However, previous studies of out-of-field teaching have indicated that schools and districts across the country are hiring large numbers of underqualified teachers to fill high-needs positions, such as secondary science and mathematics. Complicating the issue is the fact that data regarding teacher shortages, vacancies, and underqualified teaching are often incomplete or inaccessible. Prior studies have found that underqualified teaching is a particularly acute problem in low-income, high-minority, rural and urban schools and districts. Given the high number of rural districts, students of color, and the high degree of child poverty, all indicators point to Mississippi being particularly at risk of being highly affected by underqualified teaching. This dissertation aimed to explore the presence and prevalence of underqualified high school science teaching in Mississippi by examining course and teacher certification data from the fall 2022 semester. Using data obtained from the Mississippi Department of Education, an exploratory analysis of the data was conducted followed by the creation of several geographically weighted regression models which examined the relationship between rurality, poverty, and race with underqualified science teaching. Findings from the analysis showed that one in four high school science courses in Mississippi were taught by underqualified teachers; that the primary underqualification for teachers was a lack of full certification, rather than a lack of endorsement; and that while the relationships between poverty, race, and underqualified teaching were relatively consistent across the state, the relationship between rurality and underqualified teaching varied geographically and only showed a notable correlation in the Mississippi-Yazoo River delta region. Discussion of the models created, the exploratory analysis, and implications for future policy and research into underqualified teaching through spatial analysis are provided. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]