AbstractCircular RNAs (circRNAs) are a novel class of endogenous noncoding RNAs that form covalently closed continuous loops without 3′ end poly (A) tails and 5′ end caps. circRNAs are more conservative and stable than linear RNA. circRNAs can specifically bind to microRNAs as competing endogenous RNA, thereby directly or indirectly regulating the expression of related genes. circRNAs have been implicated in several cancers including gastrointestinal (GI) cancers. Some circRNAs have the potential to become biological biomarkers and therapeutic targets of GI cancers. However, the multiple functional roles of circRNAs in GI cancers remain largely unclear.