The Ukrainian refugee crisis began with the Russian invasion of Ukraine in February 2022. As of September 2025, the UNHCR has recorded 5.7 million Ukrainian refugees around the world, with 90% of this figure residing in various European countries outside of Ukraine. Older reports by the International Organization for Migration in May 2022 show approximately eight million Ukrainians as internally displaced persons. By 20 March 2022, nearly one-quarter of Ukraine's total population had been displaced due to active military hostilities with Russia. About 90% of all Ukrainian refugees are women and children; by 24 March, more than half of all children in Ukraine had left their homes, of whom a quarter had left the country as well. Men between the ages of 18 and 60 have been banned from leaving the country under Ukrainian martial law, which came into force a few hours into Russia's first military offensive into Ukraine. This ongoing escalation of the Russo-Ukrainian War has caused the largest refugee crisis in the 21st century and the fourth-largest refugee crisis in modern history as a whole, with the highest refugee flight rate globally. It is also the first European refugee crisis since the Yugoslav Wars in the 1990s and the largest one to have occurred in Europe since World War II.
The vast majority of Ukrainian refugees initially entered neighbouring countries to the west of Ukraine (Poland, Slovakia, Hungary, Romania, and Moldova). Around three million of these people then moved further west to other European countries. As of May 2025, the UNHCR reports that the countries in which the largest numbers of Ukrainians had applied for asylum, or other temporary protection, are Germany (1.2 million), Poland (1 million), and the Czech Republic (0.4 million). As of September 2022, Human Rights Watch has documented that Ukrainian civilians, particularly children, have been forcibly transferred to Russia. The OHCHR has corroborated this claim, stating that "There have been credible allegations of forced transfers of unaccompanied children to Russian-occupied territory, or to the Russian Federation itself." The United States Department of State estimated that at least 900,000 Ukrainian citizens (including children) were forcibly transferred to Russia in the first six months after the invasion. Around the same time in late 2022, more than 4.5 million Ukrainians had returned to Ukraine, owing to the withdrawal of Russian troops from all fronts but the Donbas and parts of southern Ukraine.