This review discusses how oncolytic virotherapy can be applied as a potential adjunct therapy for the potential treatment of GvHD. In addition, we highlight major emerging nonviral therapies currently studied for the treatment or prevention of GvHD. We also review the emerging oncolytic virotherapies against different hematological cancers currently eligible for allo-HSCT and highlight the potential role of the oncolytic virus MYXV to decrease GvHD while maintaining or enhancing the positive benefits of GvT.