This study used nationally representative data from the 2011 National Assessment of Educational Progress (8th-grade Science) and the 2018 National Survey of Science and Mathematics Education toward two primary purposes: (1) to examine the association between teachers' formal (university) content preparation in science and student outcomes in science; and (2) to document the prevalence and locality of Out-of-Field (OoF) science teaching in the US. The relationship between teachers' formal science preparation and students' 8th-grade science outcomes was mixed across science disciplines with a statistically significant association being observed for students' earth science outcomes. Teachers' experience teaching science and access to science instructional materials/kits were more strongly associated with student outcomes than was their formal content preparation, with statistically significant associations observed for all student outcomes (physical science, life science, and earth science). The prevalence of OoF science teaching was higher in middle schools than in high schools, as well as more frequently occurring in historically lower achieving and impoverished educational contexts.