<p>Cancer is one of the leading causes of the overall disease burden with roughly over two million new cases reported annually. As cancer encompasses various types such as lung, liver, breast, prostate, and colon cancer, advanced and reliable models are needed to investigate its mechanisms and improve therapeutic strategies. Recently, three-dimensional (3D) models, particularly utilizing hydrogels, have emerged as promising tools for modeling tumor microenvironment (TME) in cancer therapeutics owing to their favourable properties. 3D models support the construction of spheroids, bioreactors, nanochips, and organ-on-chip systems, thereby reducing the reliance on animal testing, biodegradable and biocompatible properties. Hydrogels play a pivotal role in 3D tissue models, resulting from the crosslinking of natural or synthetic polymers (e.g., collagen, fibrin, PEG, PVA), provide a highly hydrophilic environment mimicking the extracellular matrix (ECM) and enabling tumor-like architecture. This review discusses hydrogel-based platforms in the study of common cancer types (e.g., lung, liver, breast, prostate, and colon cancer) and highlights their advantages, including biocompatibility and adaptability. Moreover, it addresses the challenges associated with hydrogel models, such as limitations in replicating the dynamic TME, controlling mechanical properties over time, and ensuring reproducibility across different experimental platforms. By integrating recent findings, this review aims to provide a comprehensive overview of hydrogel applications in TME metastasis research and their potential in next-generation therapeutic development.</p>