It was investigated the influence of provenance on the yield and chemical composition of Myrtus communis L. essential oils (EOs) across Morocco. A total of 143 samples were collected from twelve populations representing three distinct biogeographic zones: the Pre-Rif, the Western Rif, and the Central Plateau. Essential oil yields varied significantly, ranging from 0.25% ± 0.13 in the IKA population (Western Rif) to 0.60% ± 0.20 in the BS population (Central Plateau), with the highest average yields recorded in populations from the Central Plateau (sub-humid zone). EOs were analyzed by gas chromatography–mass spectrometry (GC-MS), identifying 40 compounds that accounted for 93.7–99.98% of the total composition. Major constituents included 1,8-cineole, myrtenyl acetate, α-pinene, D-limonene, α-terpineol, linalool, methyleugenol, and geranyl acetate. Single-factor analysis of variance (ANOVA) and Pearson correlation analyses were used to assess the effects of provenance on both EO yield and composition. Multivariate analyses, including principal component analysis (PCA) and hierarchical cluster analysis, identified four distinct chemotypes across the natural distribution of M. communis in Morocco.These results demonstrate that provenance significantly affects both the quantity and chemical composition of myrtle essential oils, providing a quantitative basis for selecting populations with optimal EO profiles for medicinal, aromatic, and industrial applications.