The murine molecule dectin‐1 (known as the β‐glucan receptor in humans) is an immune cell surface receptor implicated in the immunological defense against fungal pathogens. Sequence analysis has indicated that the dectin‐1 extracellular domain is a C‐type lectin‐like domain, and functional studies have established that it binds fungal β‐glucans. We report several dectin‐1 crystal structures, including a high‐resolution structure and a 2.8 Å resolution structure in which a short soaked natural β‐glucan is trapped in the crystal lattice. In vitro characterization of dectin‐1 in the presence of its natural ligand indicates higher‐order complex formation between dectin‐1 and β‐glucans. These combined structural and biophysical data considerably extend the current knowledge of dectin‐1 structure and function, and suggest potential mechanisms of defense against fungal pathogens.