ConspectusSupported metal catalyst, has been one of the most important systems in the field of heterogeneous catalysis. The great complexity of both the compositions and structures of such supported metal catalysts provides a great degree of freedom for tuning their catalytic properties, which has essentially triggered the explosive growth in research on design and control active metals’ surface structures for decades. An ideal metal catalyst theoretically features maximum active sites and optimal intrinsic reactivity to facilitate a desired chemical reaction. Inspired by the catalytic concepts brought by natural enzymes and homogeneous catalysis, the fabrication of heterogeneous catalysts with atomically dispersed metal atoms has attracted much attention and been extensively explored in recent years.Atomically dispersed metal catalysts (ADMCs) including single-atom catalyst (SACs) and fully exposed cluster catalyst (FECCs), as shining stars in heterogeneous catalysts have recently drawn much attention. The advantages of ADMCs mainly include the following three aspects: (1) the fully exposed active metal atoms can realize the utmost atomic utilization efficiency and reduce the cost of catalysts; (2) the geometric and electronic structure can be effectively regulated by altering the coordination environments of metal atoms and then further tuning the catalytic performance in terms of activity, selectivity, and stability; (3) the precisely designed structures provide a promising platform for digging the structure–performance relationships of active sites with the assistance of theoretical calculations. Owing to these advantages, ADMCs have been used in thermal-catalysis, electrocatalysis, photocatalysis, etc. until now.In this Account, a summary of recent progress regarding ADMCs for heterogeneous thermal catalysis in our group will be presented from the following aspects. First, an overview of great opportunities brought by nanodiamond and its derivatives as substrates for anchoring atomically dispersed metals (ADMs) and tailoring their structures. Next, our recent progress in achieving desirable catalytic performance, including activity, selectivity, and stability over nanodiamond–graphene (ND@G) supported ADMCs will be introduced in detail. Finally, a brief outlook regarding the development directions for ADMCs by discussing current challenges and opportunities will be proposed. It is hoped that this Account can inspire the development of the rational design and various application of ADMCs.