Marine organisms are important foods for humans. Marine organisms contain large amounts of high-quality proteins. Biologically functional peptides have great potential for use as functional foods and drugs, in which they can be extracted from marine organisms. Biologically functional peptides with anticancer, anticoagulant, antidiabetic, antihypertensive, antimicrobial, antioxidant, and cholesterol-lowering activities have been described. It is very difficult to screen, extract, and purify biologically active substances from marine organisms, particularly using traditional chemical methods.Here, recent advances in extracting peptides from marine organisms are reviewed and the biological activities of various marine organism peptides are summarized.