Reactive oxygen species (ROS) are recognized as essential participants in normal cellular processes, while their intricate involvement in the emergence of various diseases, notably cancer, has garnered significant attention. Elevated levels of ROS isassociated with pro-tumorigenic signalling, heightened cell survival, increased proliferation, and DNA damage, thereby making substantial contributions to the genetic instability. Intriguingly, at elevated levels, ROS paradoxically initiate anti-tumorigenic signalling pathways, thereby instigating cell death through oxidative stress. In this comprehensive review, a focus is given on ROS generation, which encompasses both endogenous and exogenous sources that collectively referred to as oxidative stress. To provide a comprehensive understanding, an exploration of the structural, chemical, and biochemical aspects of free radicals is undertaken.Diverse sources contributing to ROS generation, including metal-mediated free radical formation is also discussed. This review additionally conducts an in-depth examination of oxidative stress within the context of cancer. Moreover, noteworthy contributions of key antioxidant enzymes, namely, superoxide dismutase, catalaseand glutathione peroxidase over the multifaceted landscape of carcinogenesis have been discussed, drawing insights from a multitude of studies. Understanding the intricate interplay between pro- and anti-tumorigenic ROS signalling pathways offers a multitude of potential avenues for cancer therapy. The disrupted redox balance observed in cancer cells presents promising opportunities for ROS manipulation, thereby emerging as a viable and innovative treatment strategy. This present review may serve as an invaluable resource, offering profound insights into the multifaceted roles of ROS in cancer while simultaneously highlighting their therapeutic potential, thereby paving the way for novel and effective cancer interventions.