In this review, we examine the genomic landscapes of lymphomas that arise from B, T, and natural killer cells. Lymphomas represent a striking spectrum of clinical behaviors. Although some lymphomas are curable with standard therapy, the majority of the affected patients succumb to their disease. Here, the genetic underpinnings of these heterogeneous entities are reviewed. We consider B-cell lymphomas, including Burkitt lymphoma, diffuse large B-cell lymphoma, Hodgkin lymphoma, and primary mediastinal B-cell lymphoma. We also examine T-cell lymphomas, including anaplastic large-cell lymphoma, angioimmunoblastic T-cell lymphoma, cutaneous T-cell lymphoma, adult T-cell leukemia/lymphoma, and other peripheral T-cell lymphomas. Together, these malignancies make up most lymphomas diagnosed around the world. Genomic technologies, including microarrays and next-generation sequencing, have enabled a better understanding of the molecular underpinnings of these cancers. We describe the broad genomics findings that characterize these lymphoma types and discuss new therapeutic opportunities that arise from these findings.