Abstract In this study, the humidity‐resistant triboelectric nanogenerators (TENGs) utilizing MoS₂‐encapsulated SiO₂ nanoparticles (NPs), aimed at enhancing self‐powered gas sensing applications, are reported. The core‐shell structure, featuring a thin MoS₂ layer uniformly grown on SiO₂, addresses common humidity‐induced performance degradation. The growth mechanism involves the decomposition and sulfidation of molybdenum species, with MoS₂ selectively nucleating on SiO₂ to form a stable, hydrophobic shell. This MoS₂ layer effectively shields the SiO₂ interface from water molecule penetration, thus stabilizing charge density and significantly reducing charge decay, even under high humidity conditions. TENGs constructed with these core‐shell NPs exhibit high triboelectric charge density and exceptional durability, retaining more than 70% output over 25 h at 99% relative humidity (RH). Furthermore, the fabricated TENG reliably powers a gas sensor array, enabling accurate gas detection in extreme humidity. This work demonstrates the potential of MoS₂‐encapsulated SiO₂ TENGs as robust, self‐powered energy solutions for environmental monitoring and wearable devices in challenging humidity conditions.