FoxO proteins represent a subfamily of the forkhead box family (Fox) superfamily of proteins. It is involved in cell proliferation, differentiation, oxidative stress, apoptosis as well as tumors and metabolic disorders by regulating cellular functions. This paper aims to summarize the role of the transcription factor FoxO in type 2 diabetes and its complications, which may add to the potential of FoxO as a therapeutic target for future research. The transcription factor FoxO is expressed in various tissues and participates in various bodily functions including cell proliferation, differentiation, apoptosis, tumor therapy, and metabolic processes, playing a crucial role in the human body. FoxO plays a positive role in attenuating oxidative stress, inflammation, and metabolic disorders, which are the main causes of type 2 diabetes and its complications. FoxO plays an important role in the regulation of type 2 diabetes and its complications, and more precise targeting studies of FoxO will help to prevent, regulate, and treat diabetes-related diseases.