Mangroves are highly valued for their ecosystem services, providing a wide range of ecological, social, and economic benefits, including their role as carbon-rich ecosystems. Recent research suggests that preserving mangrove forests can offer a cost-effective strategy for mitigating CO2 emissions. However, extensive deforestation has placed mangrove ecosystems under severe global threats. Currently, the assessment of mangrove restoration outcomes, particularly regarding soil carbon stocks, is inadequate. Therefore, this study aims to investigate the impact of restoration on soil organic carbon (SOC) in Shwe Thaung Yan, Ayeyarwady coastal region of Myanmar. The study aimed to quantify and compare carbon stocks in different soil layers, examine the carbon sequestration potential of various mangrove species, and evaluate the effectiveness of mangrove restoration efforts. Soil samples were collected in 2015 (pre-restoration) and 2021 (post-restoration) at various soil depths and analyzed for SOC concentration, organic matter content, and bulk density using the Loss on Ignition (LOI) procedure. Significant changes in soil properties were observed between 2015 and 2021, with higher SOC and carbon concentrations observed in 2021. The average soil carbon stocks in 2021 (1954.43 ± 33.24 Mg C ha−1) were approximately 2.7 times higher than the estimated carbon stocks in 2015 (732.26 ± 6.99 Mg C ha−1). Furthermore, the study revealed variations in SOC accumulation among different soil depths, with higher carbon stocks found in the upper soil layers. This study highlights the positive impact of mangrove restoration on SOC accumulation and emphasizes the significance of considering soil carbon dynamics in restoration initiatives. The findings offer valuable insights for the conservation and management of mangrove ecosystems, especially concerning their potential for carbon sequestration and their contribution to mitigating climate change.