Liquid biopsy is a non-invasive diagnostic tool that detects cancer biomarkers in bodily fluids, revolutionising early cancer detection and monitoring. This approach analyses circulating tumour DNA (ctDNA), circulating tumour cells (CTCs), and extracellular vehicles (EVs) to provide insights into tumour biology and progression. Liquid biopsy has emerged as a promising alternative to traditional tissue biopsies, offering a more accurate and less invasive approach. The technology has gained significant attention in recent years due to its potential in detecting cancer at an early stage. This review seeks to explore the advances in liquid biopsy for early cancer detection with emphasis on circulating tumour DNA and other biomarkers. Studies show liquid biopsy effectively detects cancer, particularly when combining ctDNA and CTC analysis. ctDNA analysis identifies genetic mutations, while CTCs provide information on tumour heterogeneity. Liquid biopsy also monitors treatment response and detects minimal residual disease. Advances in technologies like next-generation sequencing (NGS) and polymerase chain reaction (PCR) enhance sensitivity and specificity. Liquid biopsy applications include early detection, prognosis, and personalised treatment strategies. The technology has been explored in various cancer types, including lung, breast, and colorectal cancer. Researchers have also investigated its potential in detecting cancer recurrence and metastasis. Liquid biopsy is a promising tool for early cancer detection, offering a minimally invasive alternative to traditional tissue biopsies. Its applications in precision oncology are vast, enabling personalised treatment and improved patient outcomes. The technology has the potential to revolutionise cancer diagnosis and treatment. Further research is needed to validate its clinical utility.