Olfactory receptors (ORs) constitute the largest superfamily of G protein-coupled receptors (GPCRs). While they are classically defined by their expression in the nasal olfactory epithelium where they mediate the sense of smell, accumulating evidence has firmly established their ectopic expression in non-olfactory tissues, including the intestine, lungs, and kidney. The intestine, serving as the core site for nutrient digestion and absorption, possesses a highly complex chemical environment. To adapt to this environment, the gut utilizes a sophisticated network of "chemosensors" to monitor luminal contents and maintain homeostasis. Among these sensors, intestinal ORs have emerged as critical functional components, acting as a molecular bridge that links environmental chemical cues—such as food-derived odorants—to specific physiological responses. This discovery has significantly deepened the understanding of how dietary flavors and compounds influence intestinal physiology at the molecular level. This review systematically summarizes the expression profiles, ligand classification, and biological functions of ORs within the gastrointestinal tract. Research indicates that intestinal ORs exhibit distinct spatial distribution patterns across different gut segments and display cell-type specificity, particularly within enterocytes and enteroendocrine cells. These receptors function as versatile sensors capable of recognizing a diverse array of ligands, including exogenous dietary components, metabolic byproducts of the gut microbiota such as short-chain fatty acids, and endogenous small molecules such as azelaic acid. Upon activation by specific ligands, intestinal ORs trigger intracellular signaling cascades, primarily involving the AC-cAMP-PKA pathway or calcium influx channels. A major focus of this review is to introduce the molecular mechanisms by which these receptors regulate the secretion of gut hormones. The activation of specific ORs in enteroendocrine cells has been shown to stimulate the release of hormones such as Glucagon-like peptide-1 (GLP-1), Peptide YY (PYY), and Serotonin (5-HT), thereby modulating systemic energy metabolism, glucose homeostasis, and gastrointestinal motility.Furthermore, the critical roles of ORs in immune regulation and pathology. It highlights evidence suggesting that specific ORs contribute to the maintenance of intestinal immune homeostasis, potentially offering protection against inflammation. In addition to their involvement in inflammatory responses, ORs such as Olfr78 have been shown to regulate the differentiation and function of intestinal endocrine cells. Similarly, Olfr544 has been demonstrated to alleviate intestinal inflammation through the remodeling of the gut microbiome and metabolome. These findings collectively indicate that specific ORs hold promise as therapeutic targets for mitigating intestinal inflammation and sustaining intestinal homeostasis. Additionally, the review explores the emerging significance of ORs in cancer. While often downregulated in tumor tissues compared to normal mucosa, the activation of specific ORs by specific ligands can inhibit tumor cell proliferation, and migration, and induce apoptosis through pathways such as MEK/ERK and p38 MAPK. Conversely, other receptors such as OR7C1 may serve as biomarkers for cancer-initiating cells. In conclusion, intestinal ORs represent a vital component of the gut's sensory network, the review discusses the potential of these findings. By elucidating the precise pairing relationships between dietary components and specific ORs, novel therapeutic strategies could be developed. Intestinal ORs may become promising targets for nutritional and pharmacological interventions in metabolic diseases, inflammatory bowel diseases and malignancies.