Non-Hodgkin lymphoma is a diverse group of lymphocyte-derived neoplasms. Although a heterogeneous group of malignancies, it has become apparent that epigenetic alterations, such as disturbances of DNA methylation and histone modification, are a common occurrence in both B cell and T cell lymphomas, contributing to lymphomagenesis. As a result, the use of epigenetic targeted therapy has been incorporated into various pre-clinical and clinical studies, demonstrating significant efficacy in lymphoma, with vorinostat becoming the first epigenetic therapy to receive FDA approval in any malignancy. The role of epigenetic drugs is evolving, with its potential use in combination therapy as well as a means of overcoming chemotherapy resistance. In this review, we discuss the epigenetic alterations in non-Hodgkin lymphomas as well as provide an overview of current epigenetic drugs and their role in clinical practice, and on-going clinical trials.