Coastal settlements tend to have higher population density and economic clustering compared to inland territories. The tendency of an increasing socio-economic disbalance in favor of coastal spaces – the coastalization, has attracted the attention of the global academic community. Numerous assumptions are made on the cause of the coastalization phenomenon with the maritime activity and tourism being the primary ones. The aim of this study is to evaluate the role of the coast and tourist seaport infrastructure in the distribution of the population and tourist accommodations in cities across different sea basins of Europe. The research design implies verification of the two hypotheses: the area around the tourist seaport will have H1. The highest population density and H2. The highest density of collective accommodation facilities (CAFs) in the coastal zone of the municipality, decreasing with distance. The methodology has a two-stage structure. Firstly, the quantitative evaluation is done to allocate the tourist seaports of 28 European countries using MarineTraffic database and measure the density of population and CAFs by territorial zones using statistics. Secondly, the qualitative assessment is done presenting highlights of case studies by four sea basins (Baltic Sea, Black and Azov Sea, Northeast Atlantic Ocean, Celtic Sea, and Mediterranean Sea) and six sub-basins. 43 seaports of Europe specialize on tourism (over 90% of inbound ships). Most tourist seaports belong to the Mediterranean basin (58.1%), followed by the basin of the Northeast Atlantic Ocean (25.6%), the Azov-Black (11.6%) and Baltic (4.7%) sea basins. Cities with the tourist seaports are represented by a variety population sizes: from under 50 thousand people to over a million. Despite the differences across sea basins, the general pattern suggests a decline of population density and CAFs with the distance from the tourist seaport. Tourist seaports act as the nuclei of coastalization in Europe. The spatial proximity to the seaport has a positive influence on the density of population – the highest in the territorial zone of 2-5 km distance from the seaport, and an even higher effect on the concentration of CAFs – the highest numbers up to 1 km of the tourist seaport. We should note that population structure and tourism activity of some smaller cities are skewed towards larger adjacent cities, with the agglomeration effect outbreaking the role of the seaport.