Liver transplantation faces several biological challenges, including those related to ischemia/reperfusion injury, graft rejection or tolerance, and disease recurrence. These processes significantly impact posttransplant outcomes and highlight the need for a deeper understanding to improve patient care. The progress of omics sciences has been remarkable over the past decades, and omics techniques are widely used in clinical investigations. In this review, we have explored and briefly described investigations using omics technologies (epigenomics, transcriptomics, and proteomics) to better understand the processes affecting liver transplantation. Additionally, we have highlighted recent studies that use cutting-edge omics technologies, including single-cell RNA sequencing, spatial transcriptomics, and multiplex proteomics, often integrated into multiomics approaches, which enable a more detailed and holistic analysis of the produced data, paving the way for the discovery of precise biomarkers for liver transplant monitoring and the development of novel therapies to prevent allograft rejection.