<p>Cancer remains a leading cause of death worldwide, and while treatments have significantly improved patient survival, their cost has dramatically increased. Early identification of cancer is essential to extend the time in which medical treatment can be applied and, consequently, to reduce the negative health impacts by providing information that could lead to more effective and targeted treatments. In this context, this review highlights the potential of graphene-based nanomaterials (GBNs) in various biosensors for early cancer detection. GBNs possess a large surface area, exceptional physiochemical properties, and a strong ability to adsorb nucleic acids and amino acids, which makes it a potentially effective tool for the detection of cancer biomarkers. The review gives an overview of the recent progress in GBNs’ synthesis, the sensing mechanism allowing the conversion of receptor interactions with the target molecule into electrical signals, and the latest applications of biosensors in cancer biomarkers’ detection. Finally, current challenges and exciting opportunities for future strategies in this critical field have been discussed, emphasizing how these perspectives may guide the development of next-generation biosensors for rapid and reliable cancer detection.</p>