Only three classes of antifungal drugs are currently in clinical use. Here, we report that derivatives of the malarial drug mefloquine have broad-spectrum antifungal activity including difficult-to-treat molds and endemic fungi. Pharmacokinetic and efficacy studies of NSC-4377 indicate that it penetrates the central nervous system and is active against
Candida auris in vivo
. These data strongly support the further development of mefloquine analogs as a potentially new class of antifungal molecules.