Introduction. The article studies the identification of historical prerequisites for the formation of social policy in Spain in the late XIX-early XX centuries. The authors believe that the historical approach to this topic allows a comprehensive approach to the peculiarities of the formation of social policy in the modern world. The study of this problem since the 19th century is due to the fact that it was from that time in such European countries as Great Britain, France and Germany that the issues of the formation of social policy and its importance in society became significant.Materials and Methods. The methodological basis is based on the fundamental principles of scientific knowledge: objectivity, historicism and consistency, which predetermined the integrated use of general scientific and special approaches. The research is also based on the principle of interdisciplinarity, which allowed the socio-cultural method to be applied in this work. For the selection and systematization of sources, such methods as the analytical and the descriptive ones were used, allowing for a more accurate interpretation of documents and materials.Analysis. The history of Spain in the XIX century confirms that the turning point in the formation of social policy was the Constitution of 1869, when the rights and freedoms of the Spanish population were officially consolidated for the first time. Since then, a rather important period of social transformation has begun, which influenced the further formation of social policy in the country. The origin of social policy in Spain is also associated with the emergence of ideological trends (Krauzism, social Catholicism or Conservatism) at the end of the 19th century, formed under the influence of German socialism and the social policy of Fr. Bismarck. An important step towards the formation of social policy was the creation in 1883 of a Commission to study issues related to “the improvement or welfare of the working class in both agriculture and industry and affecting the relationship between capital and labor”. It was later renamed the Commission for Social Reforms (CRS) and gave impetus to the development of Spanish legislation on social security. The beginning of the twentieth century in Spain was marked by a political crisis, but it was during this period that great attention was paid to social issues and problems. Important laws were adopted: The Law on Industrial Accidents, The Law on the labor of women and Minors, The Law on Sunday Rest, etc. In this regard, new institutions are emerging (the Institute of Social Reforms, the Labor Inspection Service, the National Institute of Forecasting). However, many bills and social programs were never adopted, which complicated the socio-economic situation in the country. The First World War gave a new impetus to the development of social protection policies in most European countries, and in Spain in particular. The Spanish government was forced to reduce the working day to 8 hours, introduce old-age insurance for workers and employees, raise wages, and establish unemployment benefits. But the coup d’etat in 1923 and the global financial crisis of 1929 further complicated the socio-economic situation in the country. The proclamation of the Second Republic in 1931 allowed the new Government to implement a broad program of democratic transformations.Results. Thus, the historical period of the late 19th century and the beginning of the 20th century is associated with the formation of the ideology and concept of social policy in Spain. The authors of the article note that a historical digression into the problem of the formation and formation of social policy is necessary to understand the evolution of this issue and identify the relationship of historical events. Historical knowledge of the problem allows a deeper understanding of the trends in the development of social policy in modern states.