Type 2 diabetes mellitus (T2DM) is a major metabolic, multi-causal and heterogeneous disorder, characterised by chronic hyperglycaemia, which causes significant morbidity and mortality, with a considerable burden on health-care resources. The number of deaths due to T2DM highlights the importance of controlling the disease and its complications. It has been demonstrated that some proteins, protein hydrolysates, bioactive peptides and amino acids can control glucose levels directly or indirectly. Bioactive peptides have been identified in a range of food ingredients and offer the potential for incorporation into functional and nutraceutical foods. In this review, we discuss the possible mechanisms by which these compounds exert their action on glucose control such as modulating insulin production, incretin secretion, dipeptidyl peptidase-4 inhibition, regulation of glucose uptake in peripheral tissue and inhibition of some enzymes related with glucose absorption. Peptides such as IPAVF, PGVGGPLGPIGPCYE, CAYQWQRPVNRIR, PACGGFYISGRPG, WV, GPAE, GPGA, LP, IP, KLPGF and LI have shown potential for regulating blood glucose. Bioavailability and delivery of bioactive peptides are also discussed.