Student demographic data in today’s elementary and secondary schools have shown an increase in the numbers of diverse students in classrooms across the United States. This change in classroom demographics has established the need for changes to both the classroom educational environment and the preparation of our teachers. Research supports a few documented ways teachers can support both their student experiences and academic performance. Culturally competent teachers, cultural humility, and culturally relevant pedagogy are a few of the ways educators can adapt to the change in student demographics. Linking the literature to these findings will help provide an overview of several factors associated with teacher cultural competency and student academic performance. Included in the research are classroom demographics, cultural bias, teacher education and experience, relational capacity, and culturally relevant pedagogy. The research suggests that the more teachers are aware of their own bias through culturally competent teacher education, the more successful teachers are at reaching diverse students in the classroom. The goal is to provide information on the importance of teacher cultural competency and how it relates to student success. This action research, case study analyzed the relationship between teachers’ cultural competency and their students’ academic performance through a post-positive research study. Data were collected from various resources: classroom observations; teacher, parent, and student focus groups; academic data; and observations of classroom instruction. This study was a 9-week, two-intervention cycle of action research. The purpose of this action research, case study was to gain insight into teacher, student, and parent experiences and perceptions of classrooms where teachers were of Slavic descent and classrooms where teachers were of non-Slavic descent. This action research, case study aimed to answer multiple research questions to investigate why there were discrepancies between classrooms led by Slavic and non-Slavic teachers with regard to the classroom pedagogy and the academic success of Slavic students. Past research has supported a wide array of culturally responsive teaching techniques for a variety of ethnic and linguistic subgroups. The past research did not specifically look at, or study, the Slavic cultural needs in the classroom. This action research, case study specifically looked at the Slavic cultural needs at one particular school. This is the first study to provide information on the importance of culturally responsive teaching for the Slavic community and how teacher cultural humility with Slavic students can potentially improve perceptions, experiences, and academic success. This study can help fill the gap and potentially lead to further inquiry into Slavic cultural humility.