Abstract: Volatile organic compounds (VOCs) are important precursors of atmospheric ozone (O₃) pollution. To investigate the background concentration levels and characteristics of VOCs in upwind cities during O₃ pollution episodes in the Pearl River Delta (PRD) region, a mobile monitoring campaign was conducted across 12 representative areas of Heyuan City, Guangdong Province (a typical upwind city of PRD’s core polluted area) in 2024. VOCs concentrations were systematically monitored in residential zones, industrial parks, scenic areas, and the vicinity of national air quality monitoring stations. The composition characteristics and potential sources of near-surface VOCs emissions in the region were analyzed. The results showed that the average VOCs concentrations across different areas ranged from 6.0 to 134.3 µg/m³, with an overall arithmetic mean of 54.5 µg/m³. The major components of VOCs were alkanes (37%), aromatic hydrocarbons (33%), olefins (12%), and halogenated hydrocarbons (8%). Key species identified as key contributors to both VOCs concentration and ozone formation potential (OFP) included methylcyclohexane, xylene/ethylbenzene, trimethylbenzene, pentene, styrene, and toluene. Source analysis based on characteristic components and industry-specific fingerprints indicated that methylcyclohexane primarily originated from the rubber and plastic products industry and the toy manufacturing industry; xylene and ethylbenzene were mainly generated during production processes and solvent use in the plastics products industry; trimethylbenzene predominantly came from open-air solvent use and solvent application in industrial processes; pentene was mainly derived from gasoline evaporation and the plastics and rubber manufacturing industry; styrene was chiefly associated with the chemical raw materials and chemical products manufacturing industry; and toluene was closely related to the rubber and plastic products industry, the computer/communication/electronic equipment manufacturing industry, road traffic emissions, and the metal products industry.