This Special Issue on the topic of the oncogenesis of lymphoma focuses on three major areas of research: viral oncogenesis, molecular mechanisms of transformation, and putative microbial drivers. The section on viral oncogenesis highlights the role of the Epstein-Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus (KSHV) in lymphoid malignancies. Contributions discuss EBV-positive classic Hodgkin lymphoma in immunodeficient hosts, the interplay between EBV and MYC in Burkitt lymphoma, and KSHV-mediated signaling alterations in primary effusion lymphoma and multicentric Castleman disease. Another review addresses lymphoproliferative disorders in people living with HIV, examining clinical heterogeneity and emerging immunotherapeutic strategies. The molecular transformation section examines the progression of indolent B-cell malignancies to aggressive lymphomas, emphasizing genetic lesions and immune dysregulation. Additional articles explore the relevance of TNF family receptors in classic Hodgkin lymphoma, the impact of c-MYC overexpression and IGH rearrangements in chronic lymphocytic leukemia, and integrated genomic-TCR profiling to refine diagnosis and prognosis in early mycosis fungoides. Finally, studies on putative microbial drivers investigate the contribution of skin dysbiosis-particularly toxin-producing Staphylococcus aureus-to T-cell activation in mycosis fungoides, and microbiome features in breast implant-associated anaplastic large cell lymphoma, supporting multifactorial rather than pathogen-specific etiologies.