Buckwheat, a nutrient-rich pseudocereal, is known for its various biological properties, but its antinutritional factors, such as phytic acid and tannins, can hinder nutrient absorption. Fermentation improves buckwheat's nutritional profile by enhancing bioactive compounds, increasing digestibility, and reducing antinutritional factors. This review comprehensively examines the effects of fermentation and microbial strains on the nutritional composition and functional properties of buckwheat, highlighting their impact on health benefits and potential applications in diverse food products. Fermentation significantly boosts essential nutrients, including amino acids, vitamins, minerals, and bioactive compounds, while reducing antinutritional factors like phytic acid and protease inhibitors. It also enhances antioxidant, antidiabetic, hypolipidemic, anti-inflammatory, and gut microbiota-regulating properties. However, there are notable gaps in research, including limited understanding of fermentation process control, heavy metal transformation, and pathogenic microorganism effects during fermentation. Addressing these gaps is crucial for optimizing the functional properties and ensuring the safety of fermented buckwheat in the food industry. Overall, fermented buckwheat holds significant potential as a functional ingredient for gluten-free foods, nondairy beverages, and other health-promoting products that cater to specific dietary needs.