Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal malignancies, with a rising incidence and a poor prognosis that largely reflects late-stage diagnosis. Although most cases are sporadic, approximately 5–10% of PDACs occur in the context of inherited cancer susceptibility, including hereditary pancreatic cancer (HPC) syndromes and familial pancreatic cancer (FPC). Germline pathogenic variants in genes involved in DNA damage repair, cell-cycle regulation, and genomic stability—such as BRCA1, BRCA2, PALB2, ATM, CDKN2A, STK11, mismatch repair genes, and TP53—contribute to PDAC risk and may influence disease biology. This review provides an overview of the genetic landscape of hereditary and FPC, focusing on established cancer predisposition syndromes and emerging susceptibility genes. Current evidence regarding the prevalence, penetrance, and clinical relevance of germline pathogenic variants (PGVs) is summarized, together with the challenges associated with identifying individuals at increased risk. Contemporary recommendations for germline genetic testing, including the use of multigene panel approaches and limitations in real-world implementation, are also discussed. In addition, surveillance strategies for PDAC in high-risk individuals (HRI) are reviewed, and the available data on the outcomes and limitations of surveillance programs are examined. Finally, the therapeutic implications of inherited alterations, particularly in DNA repair-deficient PDAC, are outlined with reference to genotype-informed systemic treatment approaches.