Background: Migraine is a common, disabling neurological disorder with substantial genetic and environmental contributions. Dietary exposures are widely discussed by patients and clinicians as potential triggers or modifiers of attack frequency and severity. We synthesized contemporary evidence on dietary patterns, specific nutrients, and elimination strategies relevant to migraine prevention and management. Methods: We performed a narrative review of PubMed and Google Scholar (inception–August 2025) using combinations of “migraine”, “diet”, “nutrition”, “ketogenic”, “Mediterranean”, “omega-3”, and “gluten”. We prioritized randomized/controlled studies, recent systematic reviews/meta-analyses, and representative observational studies; evidence quality and applicability were appraised descriptively. Results: Higher adherence to a Mediterranean-style diet is associated with lower migraine frequency and disability in observational cohorts. Very low-calorie ketogenic diets significantly reduced monthly migraine attack frequency compared with isocaloric non-ketogenic comparators in an adult randomized controlled trial of participants with overweight or obesity (≥50% responder rate: 74% vs. 6%). Additional supportive evidence from uncontrolled studies, including those involving medium-chain triglyceride supplementation, further corroborates these findings. Omega-3 fatty acids (EPA/DHA) show prophylactic benefit in randomized trials and network meta-analyses, with favorable tolerability. Gluten-free diets may improve headaches in celiac disease and may help selected non-celiac patients. Alcohol (especially red wine) and high, irregular caffeine intake are frequently reported triggers, while evidence for specific foods/additives remains inconsistent. Weight loss and regular physical activity may further reduce burden in people with obesity. Conclusions: Current evidence supports recommending Mediterranean-style eating, consideration of omega-3 supplementation, and selective trials of ketogenic or elimination approaches in appropriate patients, alongside weight management and lifestyle optimization. High-quality, longer-duration RCTs using standardized dietary protocols and adherence biomarkers are needed to define dose–response relationships and enable personalized nutrition in migraine.