Abstract: Yunnan is a major production area for cigar tobacco in China, yet systematic research on how varying chloride ion levels in soil affect the chemical composition and flavor characteristics of Yunnan-grown cigar tobacco has been lacking. To elucidate the impact of soil chloride ions on the quality of Yunnan cigar tobacco, this study selected nine cigar tobacco samples grown in high-chloride, medium-chloride, and low-chloride soils. Routine chemical composition analysis and systematic detection and comparative analysis of aroma-contributing compounds were conducted using gas chromatography-mass spectrometry (GC–MS). Results revealed 49 conventional components and 51 aroma-contributing compounds, including 4 phenylalanine conversion products, 1 chlorophyll degradation product, 12 carotenoid degradation products, 7 non-enzymatic browning reaction products, 4 cyperene degradation products, and 23 other aroma-contributing substances. Significant differences in chemical composition and aroma characteristics were observed among the samples, each exhibiting distinct features and potential. These findings provide theoretical foundations and practical references for selecting high-quality raw materials, differentiating flavor profiles, and optimizing processing techniques for Yunnan-produced cigars.