Asteraceae plants are widely distributed with more than 25000 species and approximately 1600 genera, and fifteen Chrysanthemum species are found in Algeria. For many centuries, Chrysanthemum plants have been used in folk medicine to treat fever, arthritis, vertigo, hypertensive symptoms, and infectious diseases such as pneumonia, colitis, and stomatitis. Anti-cancer, anti-HIV-1, and antioxidant activities have been reported for some Chrysanthemum species, while only a few studies have focused on their essential oils, which have shown antibacterial, antifungal, and antimicrobial properties. Previous studies have reported the essential oil compositions of several Chrysanthemum species: C. coronarium is mainly composed of α-pinene, β-pinene, camphor, and lyratyl acetate; C. cuneifolium of α-pinene, sabinene, 1,8-cineole, camphor, and muurolol; C. yoshinaganthum of 1,8-cineole, myrtenol, and germacrene D; C. indicum from Japan of myrcene, 1,8-cineole, bornylacetate, β-farnesene, germacrene D, α-selinene, γ-cadinene, and T-muurolol; C. indicum from China of 1,8-cineole, camphor, borneol, and bornylacetate; and C. viscidehirtum of β-farnesene and limonene. This study reports the essential oil composition of the endemic species Chrysanthemum macrocarpum, which is used in Algerian folk medicine to treat fever and migraine and as a flavoring in milk drinks. Hydrodistillation of C. macrocarpum yielded 0.5% of a yellowish essential oil. Thirty-eight components were identified, accounting for 93.8% of the oil. The major components were T-cadinol (19.6%), spathulenol (12.5%), caryophyllene oxide (6.5%), and α-cadinol (5.6%). T-Cadinol was found in C. viscidehirtum (0.8%), which also contains α-cadinol (1.5%), and α-cadinol was reported in C. indicum from Japan (4.5%). Caryophyllene oxide (12.3%) was identified in the oil of cultivated C. indicum from Spain, which is also characterized by limonene (10.7%) and α-pinene (8.5%).