Lung cancer is the leading cause of cancer-related death worldwide, with poor outcomes even for those diagnosed at early stages. Current standard-of-care for most non-small cell lung cancer (NSCLC) patients involves an array of chemotherapy, radiotherapy, immunotherapy, targeted therapy, and surgical resection depending on the stage and location of the cancer. While patient outcomes have certainly improved, advances in highly personalized care remain limited. However, there is growing excitement around harnessing the power of tumor-infiltrating lymphocytes (TILs) through the use of adoptive cell transfer (ACT) therapy. These TILs are naturally occurring, may already recognize tumor-specific antigens, and can have direct anti-cancer effect. In this review, we highlight comparisons of various ACTs, including a brief TIL history, show current advances and successes of TIL therapy in NSCLC, discuss the potential roles for epigenetics in T cell expansion, and highlight challenges and future directions of the field to combat NSCLC in a personalized manner.