The right to free access to information is a fundamental human and democratic right of citizens guaranteed by international documents and laws of individual countries. In this way, citizens are given the opportunity to gain insight into data and documents held by public authorities and state bodies and to be informed of all important issues in society. Libraries, as “public institutions”, are also involved in building and strengthening a democratic society by providing free and equal access to information and ideas to their users, which is one of the basic tasks of librarians and information professionals. Library associations, primarily IFLA, in a series of documents also point to the importance of a free and equal right to access information. However, library activity in modern society, as part of the information policy of developed countries, must follow two principles: the principle of publicity and the principle of protection of privacy, i.e. it must respect the privacy of users and at the same time allow the free flow of data. In this sense, the paper gives a brief overview of the most important international human rights documents guaranteeing the right to freedom of expression and free access to information, as well as international documents mainly from library associations, which in their texts indicate the importance of free and equal access to information for all users. Finally, the paper briefly addresses the importance of protecting the right to privacy in libraries as an inseparable part of library activity in modern society.