An assembly of quantum dots (QDs) is an ideal system in which coupling between individual dots through their charge, spin, or optical excitation can be studied. [2] Apart from these fundamental aspects of physics, such systematic studies will have important implications in a wide range of fields from photovoltaic to displays and quantum information processing. [3][4][5][6] Specifically, the organic/inorganic hybrid perovskites [7] such as MAPbX 3 (MA = CH 3 NH 3 ; X = Cl, Br, I) QDs, have several attractive features such as high photoluminescence (PL) quantum yield, high diffusion length, low processing temperatures, low cost and scalable fabrication. Obviously, they have received significant attention owing to their excellent photovoltaic device performance. [8] They are also potential candidates for use in white LEDs, as wide-color-gamut backlight for LCDs, information storage, etc. [9,10] QDs of fully inorganic halide perovskite (IHP) materials such as CsPbX 3 (X = Cl, Br, I) are becoming popular due to their relatively better stability, significant photovoltaic performances, and high PL efficiency (≈90%) with concomitant narrow emission line width . [2] In the quest for high-purity green light from LEDs, the all-inorganic cesium lead halide perovskite QDs have shown promise owing to pure green emission with a narrow bandwidth and high quantum efficiency. Recalling that the efficiency of the LEDs is lower in the green/yellow spectral range, [11,12] the system investigated here may be attractive. Nanosoft composites comprising LCs as host and nanostructures as the guest is an emerging area of research that gets benefitted by the unique characters of the latter in the self-assembling features of LCs. A variety of nanoparticles have been employed to alter/tune the LC properties. In fact, QDs have received their fair share of attention in this regard. [40][41][42][43][44][45][46][47][48] Presence of QDs has been found to diminish the threshold voltage, [49] accelerate the electrooptic response, [49] photorefractivity, [50][51][52][53] increase the birefringence, [54,55] and control PL. [52,53,56] While the organic-inorganic QDs have been extensively studied in photovoltaics, it is the inorganic variety that is gaining importance in recent times. [51][52][53][57][58][59] It may be highlighted that in the previous cases of LC-QD composites, the QDs are spherical, while in contrast, IHPs form cuboids. Thus their incorporation into the LC medium can be expected to generate a tendency for self-assembled shape Fast electrically switchable anisotropic photoluminescence from a nano-soft composite comprising a nematic liquid crystal (LC) and quantum cuboids of a cesium lead halide perovskite is reported. The magnitude of the anisotropy in emission appears to be dictated by the anisotropy of the LC and the capability of the cuboids to form a linear chain, the latter being evidenced through optical and electron microscopy. Application of an ac electric field of small amplitude and its consequent coupling to the LC director ...