The article deals with the problem of protecting Ukraine’s national interests in the context of the Russian-Ukrainian war. The Internet is seen as a space for free expression of opinions, but often turns into a battlefield in the information war. The article analyses the processes of informatisation of society and the increase in the number of Internet users. The impact of the Russian-Ukrainian war on the leading Internet providers and their political position is analysed. Today, Ukraine enjoys great support from leading campaigns in this area, but the aggressor country is heavily funding war propaganda. Attention is drawn to the results of statistics on cyberattacks on state institutions and the public by the Russian Federation. It is emphasised that today state institutions, business and society in Ukraine have united to counteract the negative information influence of Russia. The structure of Ukraine’s national interests, priorities and directions of their protection are defined. Attention is focused on the fact that the Russian Federation attracts teenagers to extremist and radical activities on the Internet. This additionally threatens the national interests of Ukraine. Prevention of extremism is based on raising the legal, political and general culture of citizens, and shaping a positive image of the state. Therefore, it is justified to take effective measures to develop a powerful ideological corpus, a national idea and to adhere to the state’s strategy for European integration. It is important to establish systematic training of specialists in the field of protecting national interests in the Internet space, enhancing the preventive role of the media and institutional support for analytical, educational, propaganda and information work. The author proposes to develop a powerful system of countering manipulations on the Internet, which will include technological developments, methodology, ideological component, legal and educational measures. The author substantiates the necessity of Ukraine’s integration into the global and regional European information space; integration into international information and telecommunication systems and organisations; modernisation and certain changes in the information policy; improvement of legislation on harmonisation of national legislation with international standards; introduction of modern information and communication technologies into public administration processes, etc.