Irritable Bowel Syndrome (IBS) is a chronic functional gastrointestinal disorder. Despite its common occurrence, the pathophysiology of IBS remains not fully understood. Emerging evidence suggests that IBS is a multifactorial condition characterized by low-grade inflammation, immune system activation, impaired gut permeability, intestinal hypersensitivity, and alterations in intestinal microbiota. Recent data have highlighted the potential role of vitamin D in modulating these underlying mechanisms. Vitamin D is known to influence various cellular processes, including the regulation of the gut microbiome, immune response modulation, and anti-inflammatory effects, which may alleviate the altered gut function observed in IBS. Research indicates that individuals with IBS often have lower levels of vitamin D compared to healthy controls, suggesting a possible link between vitamin D deficiency and IBS. Vitamin D supplementation has been associated with improvements in IBS symptoms, such as bloating, flatulence, abdominal pain, constipation, and overall quality of life. The mechanisms by which vitamin D exerts these effects may involve direct or indirect modulation of immune responses, the production of antimicrobial peptides, and the regulation of gene expression related to serotonergic metabolism. Despite these promising findings, the exact pathways through which vitamin D affects IBS pathophysiology remain unclear. The aim of this review is to outline the current knowledge and evidence regarding these mechanisms, as well as the therapeutic potential of vitamin D supplementation in IBS patients. Exploring the connection between vitamin D and IBS may pave the way for innovative interventions, enhancing both management strategies and the quality of life for those affected by the disorder.