The Christian idea of solidarity was recognized as the basis for the process of European integration because it enabled reconciliation and cooperation between countries, that until recently were at odds, for the common good. Solidarity has been recognized as one of the key principles of the European Union. It is exemplified not only by the EU's redistributive policies such as the Common Agricultural Policy, cohesion policy and the EU budget, but also by the admission of less developed countries to the EU, the European Neighbourhood Policy and the European development policy. The article presents an analysis of solidarity as a fundamental value of the EU, the form of its institutionalization, and attempts to answer the question of how the EU principle of solidarity is respected during the COVID-19 pandemic. The research introduces a thesis that the coronavirus pandemic crisis has significantly weakened the importance of European solidarity. Particularly in the first period of the pandemic, the deficit of solidarity between Member States was clearly visible, even though Europeans expected cooperation and mutual assistance. Also within the EU's recovery plan and financial support under the Next Generation EU Recovery Plan, divisions and conflicts between countries have shaken European solidarity.