Microorganisms serve as a vital source of natural anticancer agents, with many of their secondary metabolites already employed in clinical oncology. In recent years, salt-adapted microbes, including halophilic and halotolerant species from marine, salt lake, and other high-salinity environments, have gained significant attention. Their unique adaptation mechanisms and diverse secondary metabolites offer promising potential for novel anticancer drug discovery. This review consolidated two decades of research alongside current global cancer statistics to evaluate the therapeutic potential of salt-adapted microorganisms. Halophilic and halotolerant species demonstrate significant promise, with their bioactive metabolites exhibiting potent inhibitory effects against major cancer cell lines, particularly in lung and breast cancer. Evidence reveals structurally unique secondary metabolites displaying enhanced cytotoxicity compared to conventional anticancer drugs. Collectively, salt-adapted microorganisms represent an underexplored yet high-value resource for novel anticancer agents, offering potential solutions to chemotherapy resistance and treatment-related toxicity.