Socioeconomic development in cities and towns is a complex and multifactor phenomenon with various dimensions and evaluation criteria. One of the simplest and most available indicators of a situation in the economic and social sphere is population size dynamics. Using the towns of Leningrad oblast as an example, we analyzed how the 2014–2016 crisis events in the Russian economy affected the population dynamics. Starting from the 1980s, the towns of Leningrad oblast have been developing multidirectionally—in some towns, the population has decreased consistently, while in other towns it has increased; some towns have exhibited stagnation. These differences have been preserved so far, but the rate of increase and decrease in the population, largely driven by migration processes, vary significantly depending on changes in the country’s economy. As a result of the study, we found that the switch in the trend of demographic development amid rapid changes in the rate of economic increase is not peculiar to all towns. We studied different scenarios of the population dynamics in the towns of Leningrad oblast during 2011–2017, and we managed to distinguish several types of urban-type settlements. Based on an analysis of territorial features of the locations of towns, we have proposed an explanation for the differences in their persistence to crisis events in the Russian economy.