Ecosystem degradation caused by deforestation, land-use change, pollution, and climate-related disturbances has significantly reduced global biodiversity and weakened the capacity of natural systems to provide essential ecosystem services. Restoring degraded ecosystems has therefore become a critical strategy for enhancing biodiversity and building climate resilience. This paper examines key restoration approaches—including passive recovery, assisted natural regeneration, native species planting, wetland rewetting, grassland rehabilitation, and coastal ecosystem restoration—and evaluates their potential to improve ecological integrity and climate-adaptive capacity. Evidence shows that restoration increases species richness, habitat connectivity, functional diversity, and structural complexity, while also contributing to climate mitigation through carbon sequestration and improved soil and water regulation. The study proposes an integrated “Assess–Plan–Implement–Monitor” framework that links restoration actions to measurable biodiversity and resilience outcomes, emphasizing climate-smart species selection, participatory governance, and long-term monitoring. Case examples from forests, peatlands, and mangrove systems demonstrate the socioecological benefits of community-led restoration initiatives. Despite challenges such as ecological time lags, management costs, and social conflicts, ecosystem restoration remains a powerful nature-based solution for addressing the twin crises of biodiversity loss and climate change. The paper concludes with policy recommendations to scale restoration effectively and equitably across diverse landscapes.