<p>Accumulated carbon storage is a crucial indicator for assessing the health of mangrove ecosystems and can suitably reflect the changes in the carbon sequestration capacity of mangrove forests over time. Unlike carbon stock for a specific year, accumulated carbon storage measures the capacity for continuous carbon sequestration in mangroves; however, spatially explicit datasets and maps on mangrove accumulated carbon storage are yet lacking on a global scale. This study pioneered the development of a global gridded dataset of mangrove accumulated carbon storage (2000–2020) at a 1 km resolution, by utilizing the most recent high-precision mangrove distribution data from the Global Mangrove Watch. This dataset captures the spatiotemporal heterogeneity of mangrove accumulated carbon storage and pinpoints hotspots of accumulated carbon stock changes at both global and regional levels. The outcomes can help identify areas requiring protection and restoration efforts, as well as prioritize policy interventions, thereby promoting the sustainable management of mangrove ecosystems worldwide.</p>