Glycans, also known as carbohydrates, are abundant upon cell surfaces, where they often mediate host–pathogen interactions. The specific recognition of host glycans by pathogenic lectins is an important process that allows the adherence of bacteria to the host epithelial surface in many species, including Group A Streptococcus (GAS). Glycan microarrays present a sensitive, high-throughput approach for identifying novel lectin–glycan interactions and can be applied in the context of whole bacteria or purified bacterial proteins.