Background: Although high rates of bereavement are evident in war‐affected populations, no study has investigated the prevalence and correlates of probable ICD‐11 prolonged grief disorder (PGD) under these circumstances. Methods: Participants were 2050 adults who participated in a nationwide survey exploring the effects of the Ukraine‐Russia war on the daily lives and mental health of Ukrainian people. Results: Of the total sample, 87.7% (n = 1797) of people indicated a lifetime bereavement. In the full sample, 11.4% met the diagnostic requirements for probable ICD‐11 PGD, and amongst those with a lifetime bereavement, the conditional rate of probable ICD‐11 PGD was 13.0%. Significant risk factors of ICD‐11 PGD included the recent loss of a loved one (6 months to a year ago), being most affected by a partner or spouse's death, loved one dying in the war, no recent contact with the deceased prior to their death, and meeting depression and anxiety diagnostic requirements. Conclusion: The study reveals that a significant percentage of Ukrainian bereaved individuals have probable ICD‐11 PGD, and identifying risk factors, particularly war‐related losses, will aid in the development of intervention and prevention programs for bereaved adults. [ABSTRACT FROM AUTHOR]