Group A Streptococcus (GAS, Strep A, Streptococcus pyogenes) causes mild human infections such as pharyngitis and impetigo, and serious infections such as necrotizing fasciitis and streptococcal toxic shock syndrome. Recurrent GAS infections may trigger autoimmune diseases, including acute rheumatic fever, and rheumatic heart disease. Combined, these diseases account for over half a million deaths per year globally. GAS is a human specific pathogen, and genomic and molecular analyses have identified a large number of GAS virulence determinants, many of which exhibit overlap and redundancy in the processes of adhesion and colonisation, innate immune resistance, and the capacity to facilitate tissue barrier degradation and spread within the human host. Our research examines the interaction of GAS with host cells and molecules at various stages of infection, with an aim to characterise mechanisms of bacterial pathogenesis.