Background: Since the beginning of Russia’s offensive war against Ukraine, over 6.3 million forcibly displaced persons (FDPs) have settled in the European Union. This study aimed to identify key mental health and psychosocial challenges among Ukrainian forcibly displaced persons (FDPs), including symptoms of depression, anxiety and PTSD, as well as barriers to implementing mental health and psychosocial support (MHPSS) in Poland, Romania, and Slovakia.