Breast cancer is the most commonly diagnosed cancer in women. The high incidence of breast cancer, which is continuing to rise, makes treatment a significant challenge. The PI3K–AKT pathway and its downstream targets influence various cellular processes. In recent years, mounting evidence has shown that natural products and synthetic drugs targeting PI3K–AKT signaling have the potential to treat breast cancer. In this review, we discuss the role of the PI3K–AKT signaling pathway in the occurrence and development of breast cancer and highlight PI3K–AKT-targeting natural products and drugs in clinical trials for the treatment of breast cancer.