Osteosarcoma (OS) is a predominant malignancy among children and adolescents, ranked third in frequency after lymphoma and leukemia. It presents a significant risk of metastasis, particularly to the lungs and distal bones, leading to severe disease progression and increased mortality. Current treatment modalities, primarily surgery and chemotherapy, are associated with considerable side effects and variable prognoses, underscoring the urgent need for novel, more effective, and less harmful therapeutic options. Flavonoids, naturally occurring polyphenolic compounds, have shown promising potential in the management of OS. This article evaluates the molecular mechanisms through which flavonoids exert therapeutic effects on OS and explores their potential in developing innovative treatments. The review provides insights into their roles in inducing apoptosis, inhibiting cell proliferation, and modulating key signaling pathways in OS cells by examining the anticancer properties of specific flavonoids such as apigenin, quercetin, and baicalein. The comprehensive analysis aims to contribute to advancing flavonoid-based therapies, opening new avenues for practical and safer OS treatments.