Exploration of triclosan analogs has led to novel diaryl ureas with significant potency against in vitro cultures of drug-resistant and drug-sensitive strains of the human malaria parasite Plasmodium falciparum. Compound 18 demonstrated EC 50 values of 37 and 55nM versus in vitro cultured parasite strains and promising in vivo efficacy in a Plasmodium berghei antimalarial mouse model, with >50% survival at day 31 post-treatment when administered subcutaneously at 256mg/kg. This series of compounds provides a chemical scaffold of novel architecture, as validated by cheminformatics analysis, to pursue antimalarial drug discovery efforts.