This study advances the evaluation of landfill gas (LFG) generation potential in Indian landfill sites by contextualizing the application of LandGEM and IPCC models to landfills characterized by high organic waste fractions, tropical climates, and limited engineered controls. Data on waste composition, quantity, age, and site-specific environmental conditions were collected from four landfills: CR Puram (Andhra Pradesh), Okhla (Delhi), and Ariyamangalam and Srinivasapuram (Tamil Nadu). Model calibration revealed critical discrepancies in methane (CH₄) predictions, with the IPCC model estimating 26% higher emissions (8.24 × 103 Mg/year) than LandGEM (6.23 × 103 Mg/year) for CR Puram, attributed to its incorporation of waste composition and degradation dynamics. Cumulative energy potential reached 2.98 × 108 kWh for Ariyamangalam by 2090, underscoring the viability of LFG-to-energy projects. However, the study highlights limitations in directly applying default model parameters to developing-world landfills, where accelerated decomposition (k = 0.1–0.15 year−1) and heterogeneous waste demand localized calibration. The findings emphasize the necessity of hybrid frameworks integrating field data to optimize methane capture, mitigate greenhouse gas emissions, and leverage landfills as renewable energy resources in India and similar regions. This work bridges a critical gap in sustainable waste management by providing actionable insights for policymakers to align methane mitigation strategies with site-specific operational and climatic challenges.