Collagen can be converted into collagen hydrolysate through chemical and enzymatic hydrolysis. Collagen hydrolysate has excellent techno-functional properties such as viscosity, emulsifying and foaming properties, solubility, and water and oil absorption capacities that can be utilized by the food and pharmaceutical industries. Furthermore, collagen hydrolysate can be converted into collagen peptides with varying structures by several purification methods, such as ultra-filtration, gel filtration chromatography and reverse-phase high-performance liquid chromatography. Collagen peptides can provide outstanding bioactivity properties such as antioxidant, Angiotensin-converting enzyme (ACE) and DPP-IV inhibitory activities. Therefore, this review aims to thoroughly discuss the techno-functional and bioactive characteristics on antioxidant, ACE, and DPP-IV inhibitory activities of collagen hydrolysate and peptides obtained from different sources, including their production and mechanisms of action. The findings showed that collagen hydrolysate and peptides from marine sources obtained higher values of techno-functional properties. The mechanism for each bioactivity is related to the relationship between the structure (residue/chain sequence, amino acid composition, size and length of sequence) and the bioactivity activity of peptides derived from marine by-products. Generally, collagen hydrolysate or peptide from marine sources shows higher antioxidant activity and ACE and DPP-IV inhibitions than bovine, porcine, and poultry.