The aim of the present work was to investigate the chemical composition variability of the essential oils (EOs) of two subspecies of Artemisia campestris L. The studied subspecies were ssp. eu-campestris (Briq. & Cav.) and ssp. glutinosa (J. Gay ex Besser) Batt. Several samples coming from different regions of collection were adopted. The plant material was harvested at full flowering phenological status. Essential oils obtained by hydrodistillation of the aerial parts of the studied plant were analyzed by GC and GC–MS. Subsequently, the antioxidant activity of these EOs were also determined in vitro using three different assays: DPPH· (2,2-diphenyl-1-picrylhydrazyl) free radicals scavenging activity, ferric reducing antioxidant power and β-carotene bleaching test. The results of the EOs analysis showed the presence of monoterpenes hydrocarbons in high amounts in the majority of studied subspecies samples. The EOs samples presented large variability of the chemical compositions for both studied subspecies; besides, a new chemotype (capillene/capillin) was identified for the ssp. eu-campestris of this plant which grows in the location of Aflou (Laghouat).