Background: Artemisia ludoviciana Nutt. (Asteraceae) is an aromatic, herbaceous, perennial plant and known commonly name as “White Sage”, “Black Sage”, “Prairie Sage” or “Cudweed Sagewort”. It is traditionally used as an antispasmodic, anthelminthic, antidiarrhoeal, stomachic, hepatic colic, appetizer, and regulator of menstruation, antimalaric and antiparasitic efficiancy. Objective: The essential oil composition of the flowering herb of A. ludoviciana (AL) was investigated and for the first time, the oil was screened for antiparasitic activity. Methods: The chemical composition of the hydrodistilled essential oil (EO) obtained from the herb with flowered of A. ludoviciana was analyzed by Gas Chromatography–Flame Ionization Detector (GC-FID) and Gas Chromatography–Mass Spectrometry (GC-MS). Results and Discussion: The outcomes showed that the major components of oil were camphor (40.6%), 1,8-cineole (25.5%) and camphene (4.7%), among 45 identified compounds, comprising 98.5 of the total oil. In addition, the oil was tested against Acanthamoeba castellanii, Leishmania infantum and Trichomonas vaginalis. Conclusion: In this study, it is first demonstrated that A. ludoviciana essential oil (AL-EO) is effective against three important parasites.