Student performance in high school Earth Science coursework often depends upon access to high quality teaching and resources. This study employed a non-experimental correlational research design to explore teacher-level and school-level variables and their relationship to students' Earth Science performance. The theoretical framework is derived from studies that suggest both teacher and organizational characteristics influence students' academic outcomes. Statewide census data were collected from a sample of Earth Science teachers (N = 2457) and Earth Science students (N = 153,749) in New York State during the 2016-2017 academic year. Teacher-level variables included certification status, professional age, course load in Earth science, and teacher isolation; while the school-level variables included Earth Science performance, test-taking percentage, socioeconomic status, locale, ethnicity, and English language proficiency. Results indicated that nearly a quarter of Earth Science teachers were teaching out-of-field, with a higher incidence in urban schools, where nearly half of all Earth Science teachers were not certified in the subject. A multivariable regression model with a subset of isolated Earth Science teachers (n = 528) indicated student performance was predicted by socioeconomic status, ethnicity, English language proficiency, and the prevalence of Earth Science participation in the school. These findings have implications for policy makers to institute reforms in teacher education and precollege Earth Science instruction, particularly in educational contexts that serve historically marginalized students, with the aim of promoting equity in diverse educational contexts. Recommendations include increasing precollege Earth Science access in the United States, improving pedagogical knowledge, and enhancing the teaching of Earth Science through informal settings.