In this paper, we explore marine bioactive peptides with anticancer potential sourced from various marine organisms, including tunicates, sea sponges, and mollusks. Peptides like Stylisin and Papuamides have been isolated, identified, and modified to enhance their activity, with many advancing to clinical trials due to their diverse biological activities, promising prospects in medicine. Enzymatic hydrolysis is a favored method for extracting peptides from marine proteins, particularly from sponges known for their rich bioactive compounds. Compounds such as Jaspamide and Homophymins exhibit potent cytotoxic activity against cancer cells, underscoring their therapeutic potential. Additionally, peptides from ascidians and mollusks, such as Aplidine and Kahalalide F, demonstrate significant anticancer properties. This study also explores peptides influencing apoptosis, microtubule dynamics, and angiogenesis, providing insights into potential mechanisms for cancer treatment. While peptides like Neovastat and mycothiazole target known pathways, others such as patellamides act through unknown mechanisms, highlighting the intricate interactions of marine peptides with cancer cells. Overall, marine-derived peptides show promise as valuable candidates for developing novel anticancer therapies.