Abstract: Lubricating grease can effectively reduce friction between mechanical components, extend equipment service life, and lower energy consumption. The introduction of additives can significantly improve the performance of lubricating grease. Among them, two-dimensional (2D) nanomaterials have shown remarkable potential in enhancing anti-friction and anti-wear properties due to their nanoscale thickness, low interlayer shear strength, high specific surface area, and excellent stability. Based on this, this paper systematically summarizes four lubrication enhancement mechanisms of 2D nanomaterials in lubricating greases: filling surface asperities, forming tribofilms, interlayer sliding, and synergistic lubrication. The latest research progress on typical 2D nanomaterials—including graphene, hexagonal boron nitride (h-BN), molybdenum disulfide (MoS₂), tungsten disulfide (WS₂), layered double hydroxides (LDHs) and MXene—in lubricating greases is discussed. The challenges of applying 2D nanomaterials in practical lubrication scenarios are analyzed, and future prospects are presented to promote the development of 2D nanomaterial-based grease additives and their application under various lubrication conditions.