Background: Article analyzes various national and international aspects of the state of the system of legal support of public order and social security related to mass events.  Objective: to develop organizational and legal solutions aimed at creating an effective approach to solving issues of law enforcement and social security during the preparation and holding of mass public events.  Methods: dialectical method was chosen as the main research method.  Results: The article highlights the administrative-legal and organizational-tactical measures used by the internal affairs bodies and the resource enforcement of the law and social security during the preparation and holding of public events of various kinds. The authors highlight the legal and organizational bases for law enforcement and social security during the preparation and holding of public events in foreign countries.  Conclusions: New approaches to ensuring social security have been proposed for both internal affairs units and sanitary and epidemiological services in connection with the spread of the COVID-19 pandemic.