Chronic mucocutaneous candidiasis can be caused by an Inborn Error of Immunity, especially those affecting TH-17 / IL-17 responses. Through in-depth immunophenotyping and functional assays, we reveal the association between homozygous carriage of the common p.R381Q IL-23R genetic variant and increased candidiasis susceptibility, relying on disrupted IL-23-mediated IL-17 immunity.