Since its first written description around 3000 BC until the present day, cancer has stood as a leading global cause of death, claiming the lives of 1 in 6 individuals. Due to its widespread impact and lethality, it remains one of the most explored yet most challenging disease for the global scientific community. Throughout history, various plant extracts have been used in treating numerous diseases, including cancer. These natural extracts are regaining attention due to their therapeutic benefits and lesser side effects. Thymoquinone, chemically 2-isopropyl-5-methylbenzo-1,4-quinone, constitutes the primary bioactive component of the plant Nigella sativa. Extensive research across in vivo, in vitro models, and clinical trials has revealed Thymoquinone's noteworthy therapeutic potential against cancer. Thymoquinone has shown promising anti-cancer activity in various cancers including breast cancer, lung cancer, prostate cancer, colorectal cancer, cervical cancer, pancreatic cancer, gastric cancer and blood cancers. However, there are challenges such as limited clinical trials, low bioavailability, and the need for more research to understand its long-term safety and effectiveness. This article provides a comprehensive and thorough review of thymoquinone, covering its effectiveness across various malignancies, the molecular signalling pathways it influences, and its role in triggering apoptosis and inhibiting inflammation, angiogenesis, and metastasis. Additionally, the review includes a thorough examination of thymoquinone's pharmacokinetics and safety, making it the first of its kind in its comprehensiveness.