MXenes can be denoted with the formula M n+1 X n T x (n 1-3), where M is an early transition metal (Sc, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, or W), X is carbon and/or nitrogen, and T x stands for a surface functional group (O, OH, and/or F, etc.). [8] MXenes have a lattice with hexagonal lattice symmetry inherited from their parent MAX phase and have a superior electrical conductivity (6000-8000 S cm −1 ) due to their metallic backbone. [1,8] Abundant surface functional groups provide a large number of active sites on the surface of MXenes, and this has tremendous potential for surface modification and the highly efficient loading of active substances. [9][10][11][12] Additionally, MXenes have good thermal conductivity, [6] a tunable bandgap and excellent mechanical strength, [13,14] thus having great prospects in the fields of energy conversion and storage, [15][16][17] electromagnetic interference (EMI) shielding and absorption, [18][19][20] sensing, [21,22] environmental protection, and so on. [23,24] However, similar to other 2D materials, MXenes also have a propensity for "face to face" stacking and aggregation due to strong van der Waals forces, which greatly limits their performance in practical applications. [25,26] Recently, to address the stacking problem for a high surface utilization and obtain functional MXene materials with well-tailored structures, intense efforts from different aspects, such as surface modification, [27] heteroatom doping, [28] buckling and crumpling, [29][30][31][32] introducing interlayer spacers, [33] templating, [34] and crosslinking [35] have been made.Ways of assembling MXenes into 3D structures at the macro and/or microlevel are greatly needed to overcome the restacking problem of 2D materials, and have been extensively studied. [18,36,37] The 2D MXene nanosheets can be used as building blocks to construct MXene assemblies with desired structures by well-designed methods. Their excellent properties are expected to be inherited by the assemblies, thus essentially expanding their applications. Hence, there is a great need to summarize recent progress in the design of MXene assemblies for diverse applications.Previously, several reviews on the synthesis, properties, and applications of MXenes have been published. [8,15,25,[38][39][40][41] However, none of them have summarized the latest advances on MXene from an assembly perspective. A timely and focused progress report of MXene assemblies is expected to further accelerate the development of these emerging materials and promote their applications. Here, recent efforts on MXene assemblies and the corresponding assembly strategies are reviewed. To facilitate the discussion, the assemblies are classified into three categories according to their dimensional structures at the macro and/ or microlevels. These are, 2D assemblies, 2D macroassemblies Since their discovery in 2011, transition metal carbides or nitrides (MXenes) have attracted a wide range of attention due to their unique properties and promise for use in a variety of appl...