Introduction: Salvia is the largest genus within the Lamiaceae family, comprising over 1,000 species of considerable importance to the pharmaceutical, food, and cosmetic industries. Salvia nemorosa L. (S. nemorosa) is a less explored representative of this genus, associated with antioxidant, analgesic, antimicrobial, antifungal, antidiabetic, and acetylcholinesterase inhibitory activities. This study aimed to evaluate the phytochemical profiles of essential oils (EOs) obtained from four wild populations of S. nemorosa L. collected across different regions of Bulgaria. Methods: The phytochemical profiles of the four samples were analyzed using gas chromatography-mass spectrometry (GC–MS). In addition, histochemical analysis of lipid accumulation was carried out with Sudan III staining, and sections were examined under a light microscope equipped with a digital camera and image processing software. Results: GC–MS analyses revealed the presence of sesquiterpene hydrocarbons, monoterpene hydrocarbons, oxygenated sesquiterpenes, and oxygenated monoterpenes. The predominant compounds were germacrene D (17.64–41.34%), β-caryophyllene (9.50–22.38%), and caryophyllene oxide (4.66–7.35%), with other notable constituents including sabinene (6.88–21.89%), bicyclogermacrene (7.67%), and phytol (5.21%). Based on the high content of these compounds, the EOs may exhibit considerable antioxidant, antimicrobial, and anti-inflammatory activities. Histochemical analysis confirmed the presence of lipid structures, as indicated by orange-stained droplets. These findings provide valuable insights into the phytochemistry of S. nemorosa L., highlighting its promise for future pharmacological and industrial applications.