Anchorage of tissue cells to their physical environment is an obligate requirement for survival that is lost in mature hematopoietic and in transformed epithelial cells. Here we find that a lymphocyte lineage-restricted transcription factor, Aiolos, is frequently expressed in lung cancers and predicts markedly reduced patient survival. Aiolos decreases expression of a large set of adhesion-related genes, disrupting cell-cell and cell-matrix interactions. Aiolos also reconfigures chromatin structure within the SHC1 gene, causing isoform-specific silencing of the anchorage reporter p66^Shc and blocking anoikis in vitro and in vivo. In lung cancer tissues and single cells, p66^Shc expression inversely correlates with that of Aiolos. Together, these findings suggest that Aiolos functions as an epigenetic driver of lymphocyte mimicry in metastatic epithelial cancers.