The World Health Organization (WHO) has mentioned cancer as the second-leading cause of death worldwide, resulting in the loss of ten million lives per year. Although, enormous strides in the fields of cancer research and medicine have helped in effective management of cancer, it is still not completely curable. Thus, the forage for more constructive, economical and safe treatments has led to the revelation of bioactive compounds. These naturally occurring molecules have been seen to produce medicative effects on various tumour cell lines. They are found in the form of secondary metabolites from different plants, fungi and bacteria and have shown response against cancer. This study, involves an in-depth study of the activity of different bioactive compounds against cancer. Plant-derived bioactive, such as curcumin, myricetin, geraniin and tocotrienols, have been found to affect the dictum of cell growth and apoptosis and possess antitumour possessions, which were found to inhibit augmentation in many cancer cell lines, like lung, pancreatic, breast, prostate, skin, stomach and colon cancers. As per the literature considered, the impacts of bioactive compounds, like curcumin with an IC50 value of 49 ± 2.08 μg/ml against MDA-MB-231 cell lines and myricetin with an IC50 value of 690 mM, have been seen to prevent hFEN1 attachment, thereby inhibiting colon cancer, geraniin with a concentration of 10 μM reduced the NF-κB expression in C666-1 cells. Endophytic fungi like Penicillium sp. released compounds such as podophyllotoxin and diosgenin that are able to act at the transcriptional level and prevent the growth of metastatic cells. Fucoxanthin, a marine-derived bioactive, can induce cell growth arrest, apoptosis and autophagy in cells. Endophytic actinomycetes have shown to produce bioactive compounds that showed toxicity against human lung cancer cells. Therefore, this chapter would portray the ability of novel bioactive compounds, derived from natural sources to treat cancer, with special emphasis upon their origin, mechanism and future prospects of their usage in cancer treatment and prevention.