Stroke is associated with a high incidence and disability rate, which seriously endangers human health. Oxidative stress (OS) plays a crucial role in the underlying pathologic progression of cerebral damage in stroke. Emerging experimental studies suggest that polyphenols have antioxidant potential and express protective effects after different types of strokes, but no breakthrough has been achieved in clinical studies. Nanomaterials, due to small characteristic sizes, can be used to deliver drugs, and have shown excellent performance in the treatment of various diseases. The drug delivery capability of nanomaterials has significant implications for the clinical translation and application of polyphenols. This comprehensive review introduces the mechanism of oxidative stress in stroke, and also summarizes the antioxidant effects of polyphenols on reactive oxygen species generation and oxidative stress after stroke. Also, the application characteristics and research progress of nanomaterials in the treatment of stroke with antioxidants are presented.