Formononetin (FMNT), a flavonoid found in legumes and grasses, has shown significant anti-inflammatory and antioxidant properties. This review summarizes the mechanisms by which FMNT exerts its effects against inflammation and oxidative stress, highlighting its potential in treating various diseases. FMNT targets multiple pathways, including the COX2/PGE2, NF-κB, MAPK, JAK-STAT, and NLRP3 inflammasome pathways, to reduce inflammation and oxidative stress. It also activates the Nrf2/HO-1 pathway, PI3K/AKT, SIRT1, and PPARγ, enhancing antioxidant defenses and reducing oxidative damage. FMNT has been shown to alleviate inflammation in conditions such as cancer, neurological diseases, fibrotic diseases, allergic diseases, metabolic diseases, cardiovascular diseases, gastrointestinal diseases, and autoimmune diseases. Despite its potential, FMNT has low bioavailability and water solubility, but its derivatives, such as FMNT-7-O-phosphate and sulphonated FMNT, have improved these properties. FMNT is non-toxic at low doses but may cause toxicity at high doses. Future research should focus on optimizing its use, exploring its mechanisms in more detail, and developing it into products for medical, food, and cosmetic applications.Formononetin (FMNT), a flavonoid found in legumes and grasses, has shown significant anti-inflammatory and antioxidant properties. This review summarizes the mechanisms by which FMNT exerts its effects against inflammation and oxidative stress, highlighting its potential in treating various diseases. FMNT targets multiple pathways, including the COX2/PGE2, NF-κB, MAPK, JAK-STAT, and NLRP3 inflammasome pathways, to reduce inflammation and oxidative stress. It also activates the Nrf2/HO-1 pathway, PI3K/AKT, SIRT1, and PPARγ, enhancing antioxidant defenses and reducing oxidative damage. FMNT has been shown to alleviate inflammation in conditions such as cancer, neurological diseases, fibrotic diseases, allergic diseases, metabolic diseases, cardiovascular diseases, gastrointestinal diseases, and autoimmune diseases. Despite its potential, FMNT has low bioavailability and water solubility, but its derivatives, such as FMNT-7-O-phosphate and sulphonated FMNT, have improved these properties. FMNT is non-toxic at low doses but may cause toxicity at high doses. Future research should focus on optimizing its use, exploring its mechanisms in more detail, and developing it into products for medical, food, and cosmetic applications.