In the contemporary world, trust is becoming not only a social, moral and political, but also an economic category. Trust is related to and associated with the level of transaction costs in the economy, therefore, a society of low trust (low trust of citizens to each other; low trust of the state to citizens and citizens to the state; low trust in digital systems and technologies) cannot provide the required level of economic growth and social welfare. In a digital society, the problem of trust becomes even more urgent: economic transactions are carried out in mobile applications on smartphones; payment for goods and services is made through the mobile phones; job search is shifting to social networks; information is more and more presented via internet channels. How trust is generated in these digital systems; digital sources of information; digital economy? What is the level of this trust? These are the key research questions for this article. In its first part, the authors examine comparative studies of trust and reveal the nature of the transformation of trust: from personal trust to institutional trust and then digital trust. The second part presents results of an empirical study of digital trust (using the example of St. Petersburg): telephone survey, N=1032, the sample is representative in terms of the main socio-demographic parameters); a series of in-depth interviews. In the final part of the article, the authors characterize the main social effects of digitalization and identify obstacles to the development of digital trust.