The ongoing SARS-CoV-2 pandemic has devastated the global economy and claimed more than one million lives, presenting an urgent global health crisis. To identify host factors required for infection by SARS-CoV-2 and seasonal coronaviruses, we designed a focused high-coverage CRISPR-Cas9 library targeting 332 members of a recently published SARS-CoV-2 protein interactome. We leveraged the compact nature of this library to systematically screen SARS-CoV-2 at two physiologically relevant temperatures (33 ºC and 37 ºC) along with three related coronaviruses (HCoV-229E, HCoV-NL63, and HCoV-OC43), allowing us to probe this interactome at a much higher resolution relative to genome scale studies. This approach yielded several new insights, including unexpected virus-specific differences in Rab GTPase requirements and GPI anchor biosynthesis, as well as identification of multiple pan-coronavirus factors involved in cholesterol homeostasis. This coronavirus essentiality catalog could inform ongoing drug development efforts aimed at intercepting and treating COVID-19, and help prepare for future coronavirus outbreaks. Overall design: Focused CRISPR screens targeting host factors in the SARS-CoV-2 interactome were performed for SARS-CoV-2, HCoV-229E, HCoV-NL63, and HCoV-OC43 coronaviruses.