Sacred groves are traditionally protected forest patches conserved by local communities through religious and cultural practices. While their ecological and cultural importance is well recognised, their role in climate change mitigation through carbon storage remains underexplored. This study assesses the carbon sequestration potential of selected sacred groves in and around the Union Territory of Puducherry, India. Three representative groves—Suriyanpet, Urani, and Kizhputhupet—were selected based on size, vegetation density, and disturbance levels. A non-destructive sampling approach using 20 m × 20 m quadrats was employed to estimate above- and below-ground biomass using standard allometric equations, followed by carbon stock estimation through established biomass-to-carbon conversion factors. The results indicate that sacred groves function as significant carbon sinks despite fragmentation and increasing anthropogenic pressures. The study underscores the need to conserve and restore sacred groves as effective nature-based solutions for climate change mitigation, while also supporting biodiversity conservation and cultural heritage preservation.