RNA epitranscriptomic markers, such as N6-methyladenosine (m6A) and N1-methyladenosine (m1A), are essential for controlling RNA metabolism including splicing, transport, decay, and translation. Mounting evidence suggests that dysregulation of RNA modifications plays a critical part in governing the behavior of cancer cells, encompassing maintenance of stemness, hyperproliferation, invasion, metastasis, metabolic reprogramming, and immune evasion. This chapter explores the emerging understanding of how RNA modifications contribute to these critical aspects of cancer cell behavior, with a particular focus on gastrointestinal (GI) cancers that represent over a quarter of all cancers. It also highlights the potential of targeting RNA modifications as therapeutic interventions in different GI cancer types based on the published studies. Understanding the pivotal role of RNA modifications in the pathogenesis of GI cancers offers promising avenues for developing novel and personalized cancer therapies.