Today migrations represent a major political, social and human concern for the global agenda as they affect governments, the Catholic Church as well as other faith-based communities, local communities, and countless individuals. In recent years individual scholars have studied the significant impact and transforming power of human mobility as portrayed in the Bible, in the experience of major religious figures, in the social teaching of the Church and in specific religious traditions. In order to responsibly address the challenges posed by migration, local Churches in sending, transit and receiving countries around the world are called to promote theological reflections and studies on the phenomenon, as well as to enable and encourage concrete pastoral actions. A biblical, theological and pastoral reflection on today's migrants and refugees is therefore very timely and useful. To such extent, the Scalabrini International Migration Institute (SIMI), the International Union of Superiors General (UISG), and the Union of Superiors General (USG) organized and held an online international conference on the Theology of Human Mobility in the 21st Century on 20-22 September 2021. This book presents the proceedings of the conference, aiming at providing valuable information and insights for both biblical and theological research, as well as for the pastoral planning and the formation and training of pastoral workers.