Natural anticancer compounds, derived from plants, marine organisms, fungi, and microorganisms, exhibit significant therapeutic potential in oncology. These bioactive compounds play a crucial role in inhibiting tumor growth, promoting apoptosis, and suppressing malignancy through diverse mechanisms. This review explores the various classes of natural anticancer agents, including polyphenols, alkaloids, terpenoids, and peptides, highlighting their mechanisms of action and clinical relevance. Key examples include resveratrol, curcumin, paclitaxel, and epigallocatechin gallate, along with marine-derived compounds like bryostatin-1 and discodermolide, which have demonstrated promising anticancer properties. Despite their potential, challenges such as bioavailability, toxicity, and formulation hinder their clinical translation. However, advancements in drug delivery systems and combination therapies present promising strategies to overcome these limitations and enhance therapeutic efficacy. Further research is essential to optimize pharmacokinetic properties, understand molecular interactions, and explore synergistic combinations for developing more effective and safer anticancer treatments.