We examined how the shift in learning environment from in-person to online classes, due to the COVID-19 pandemic, impacted three constructs of student engagement: behavioral engagement, including students’ frequency of participating in class discussions, meeting with instructors, and studying with peers outside of class; cognitive engagement, including students’ sense of belonging and self-efficacy; and emotional engagement, including students’ attitudes toward science, their perceived value of the course, and their stress. Seventy-three undergraduate STEM students from across the country completed five-point Likert-style surveys in these areas of student engagement, both prior to their science course transitioning online and at the end of the spring 2020 semester.