The term deagrarianization refers to the dwindling importance of agrarian activity as the economic and social basis of a rural area. Deagrarianization is reflected in the declining number of people engaged in agricultural production and a reduction in the relative importance of agricultural incomes. In addition to the economic consequences, deagrarianization also erodes the importance of the rural population in territorial organization and management and social functioning in rural areas. However, it is also true that the simultaneous shift towards the service economy in present-day rural economies and societies has not led to the disappearance of the rural space but, instead, given rise to new and multiple forms of rurality. The priority objective of the research on which this paper is based is to gain insight into the rural deagrarianization processes in Spain through the specific case of Cantabria. In order to analyze these dynamics, a series of basic indicators have been used. In order of importance, the main indicators employed were those related to the recent dynamics of agriculture, livestock, and forestry activity and the occupational structure of the population as regards its sectoral distribution, with particular attention being paid to the relative importance of livestock and forestry activities in relation to the direct exploitation of territorial resources. In the past, primary sector activities were very important in Cantabria, but their importance has steadily declined in both absolute and relative terms until reaching the current situation. In 2023, only 4579 people have been employed in agriculture out of a total of 214,574 active people (2.13%). It is very significant that between 2012 and 2021, the total number of employed people increased by 9.08% in Cantabria while the proportion of people employed in agricultural activities decreased by −12.90%. Farming is no longer the rural occupation par excellence; however, it continues to be important in most Cantabrian rural municipalities. The territorial distribution is even more revealing. Southern mountain municipalities can be considered the last stronghold of agricultural activity since, in most cases, more than a quarter of their active population is employed in this sector. These are also the rural areas with the highest levels of depopulation. In contrast, other activity sectors have also gained importance in rural areas, although not in the same way. In general, there is less service economy employment in inland rural municipalities, except in those that are county capitals offering services. Some rural, peri-urban, and coastal areas where tourism is more strongly developed also reach high values.