Transformation processes in the financial sector of Ukraine are an objective reality of nowadays, associated with new challenges, and threats. The most vulnerable to such changes are households that are directly involved in such economic processes as the production of goods, redistribution of resources, consumption of goods produced. The purpose of the article is to increase insight into the theoretical foundations of the formation of a mechanism for guaranteeing the financial security of households. It is substantiated that the mechanism of guaranteeing the financial security of households is a set of organizational forms of financial relations aimed at creating the necessary conditions for the financial and social development of all household members. The structure of the mechanism for ensuring the financial security of households consists of methods, tools, and levers that systematically interact with each other and create favourable conditions for the life of all household members, help eliminate or minimize financial threats to their financial security. It was found that financial security enhancement of households is carried out directly by household members. But the conditions for the effective functioning of the mechanism for ensuring the financial security of households are provided by the State. Given the growing trends of the financial needs of people, their satisfaction remains one of the priorities of public policy. The directions of development of the mechanism of guaranteeing of financial security of households are offered, among which: formation of possibilities for financial resources increase; enhancement the protection of financial resources of households; increasing the financial literacy of the people; saving financial resources of the population; effective prevention of existing and potential threats.