<p>Reactive oxygen species (ROS) homeostasis is an essential process that enables cells dynamically regulate their ROS levels, thereby ensuring survival and the execution of diverse physiological functions. ROS, a group of highly reactive molecules that serve as both critical signaling molecules and potential toxic agents, are central regulators of this process. Dysregulation of ROS homeostasis can impair cellular and organismal physiology, ultimately contributing to disease pathogenesis, which is a phenomenon observed throughout the lifespan. However, the precise mechanisms underlying these processes remain poorly understood, and the therapeutic potential of targeting ROS homeostasis regulation for disease intervention has not been systematically elucidated. This review provides a comprehensive overview of the diverse roles of ROS and their metabolic associations. It offers an in-depth discussion of the regulatory mechanisms underlying ROS homeostasis and their influence on processes such as cellular metabolism, cell death, and cell survival. By modulating cell fate, ROS play a broad and integral role in the pathogenesis of various diseases. Finally, this review systematically summarizes therapeutic interventions targeting ROS homeostasis. By elucidating the critical roles of ROS homeostasis in cellular physiology and disease treatment, this review aims to advance the discovery of potential biomarkers as well as the development of novel therapeutic approaches based on ROS homeostasis.</p>