This article presents a methodology for the formation of an integrated multicomponent index of socioeconomic development of Russian cities. By analogy with the best foreign practices, the index is built on four key groups of indicators or sub-indices of the main components of the urban development: level of economic development, level of human development, provision of social infrastructure, and the quality of the urban environment. Direct and calculated indicators of municipal, regional and departmental statistics were used. Unlike international and Russian indexes, which consider single cities or centers of certain population sizes, on the basis of the proposed index, an assessment of the level of socioeconomic development of more than 95% of the country’s cities and towns is made. In general, Russian cities and towns are characterized by moderate differentiation of the index of the level of socioeconomic development. Among the leaders, in addition to both capitals—Moscow and St. Petersburg, with a balanced contribution of all sub-indices, there are resource cities with increased values of the components “economic development” and “social infrastructure”, as well as science cities and satellite towns of the country’s largest agglomerations with a high level of urban development and an improved quality of human development. The worst positions are characteristic of small peripheral towns, in which a low level of economic development is superimposed on the unsatisfactory state of the urban environment, low indicators of the provision of social infrastructure and the quality of human development.