Background: The COVID-19 pandemic has underscored the essential role of first responders, other public safety personnel (PSP), frontline healthcare professionals (FHP), and other frontline workers in protecting all Canadians. PSP and FHP are critical population defences against the COVID-19 pandemic. PSP and FHP are often tasked to work short-handed, long hours, facing the threat of contagion for themselves and their families. In serving Canadians, PSP and FHP are often tasked to provide communication, direct care, or support outside of their usual job description, expertise, experience, or level of comfort. Objective: The COVID-19 Readiness Resource Project (CRRP) was launched in March 2020 in response to the pandemic to provide PSP with the support to safeguard and protect their mental well-being, minimize the development of compassion fatigue, moral injury, and burnout, as well as preserve their ability to function in these critical roles, both during and after the emergency pandemic responses subsided. The CRRP is a national online knowledge hub serving as a vehicle for trusted information, guidance, and access to virtual self-help material. Methods: Quality improvement practices were adopted to develop a real-time iterative approach to inform the development and implementation of the CRRP. The project was supported by federal, provincial, and municipal government agents who partnered with several organizations. The CRRP content creation, development, and dissemination included patient-oriented approaches, PSP input, and knowledge translation and mobilization best-practices. Frontline PSP and FHP worked with their leaders and diverse experts from across Canada to deliver content and support PSP throughout wave one of COVID-19. Results: PSP continue to encounter evolving challenges throughout the pandemic. The CRRP provided support tools derived from the extant peer-reviewed literature on pandemics, epidemics, and disaster mental health. The available material was synthesized and tailored to the specific needs of PSP and FHP based on direct consultation with frontline members and leaders. Resources created included accessibly written content spanning 20+ categories, with videos, guided audio-recorded stress management exercises, and videos from an interactive Virtual Town Hall Series. All resources and content were made available to all PSP in Canada and internationally. Conclusion: The content developed for the CRRP will be invaluable in informing future research on rapid evidence-based resource development in the face of a crisis. In addition, the challenges experienced by the CRRP team during the development and delivery can help inform future crisis preparations and research on crisis response, disaster psychiatry, and developing actionable steps for delivering equitable mental healthcare through a culturally competent and cultural humility lens.