COVID-19 can worsen the physical health of individuals with serious mental illness, a vulnerable group already facing physical health disparities. COVID-19 is further reducing access to physical health care due to shutdown of services deemed “non-urgent” and overcrowding of emergency services. Management of chronic diseases, highly prevalent in this group, is undermined due to exacerbation of psychiatric disorders, reduction in availability of social support, and worsening of negative social determinants of health. In this commentary, we discuss the challenges experienced by this group and offer mitigation strategies to reduce: (1) inequalities in access to physical health care; and (2) disruptions to the management of chronic physical conditions in the face of COVID-19. Recommendations include coordinated efforts by health authorities, primary and mental health care organizations, researchers, policymakers, and other stakeholders. These efforts should ensure equitable access to physical health care and implementation of innovative programs to protect the physical health of people with serious mental illness during and following the pandemic.