Transition metal dichalcogenides (TMDCs) are lamellar materials with strong covalent in-plane bonding and weak van der Waals inter-layer interaction, classifying them as van der Waals solids. Tunable bandgap, high carrier mobility, and large surface area make these materials relevant for different applications in electronics, optoelectronics, and catalysis. In addition, because they can possess meta-stable crystal structures (octahedral or distorted octahedral), they are candidates for a considerable number of applications, such as hydrogen evolution reaction (HER) and electrode materials for sodium ion batteries. As a consequence of different bonding energies (strong in-plane and weak inter-layer bonding), isolation of single monolayers is achievable, which creates a high surface area, induces quantum confinement and bandgap transformation. This alluring feature results from a lack of symmetry due to the reduction in the size to a single monolayer. Due to these unique properties and numerous potential applications of TMDCs monolayers, the preparation of single layer materials and control of their size have attracted much attention. Different thin layer preparation techniques have been developed and applied over the years, such as exfoliation techniques, substrate growth techniques, and colloidal synthesis. But so far, no studies have succeeded in synthesizing size-controlled and well-dispersed nano-monolayers. Colloidal synthesis of TMDCs could be a promising strategy to produce a scalable amount of nanosheets by modifying the experimental parameters. It has been almost one decade since the first colloidal synthesis of WS2 nanosheets was developed, yet this field suffers from the lack of a direct colloidal protocols to produce both well-dispersed and size controlled WS2 nanosheets. Previous work from our group reported a protocol to produce 1T-WS2 nanosheets, and by a modification, 2H-WS2 nanoflowers were also synthesized. However, these 1T-WS2 nanosheets were severely defected. Zhou et al. developed another hot injection protocol to synthesize WS2 nanosheets. Although they managed to control the number of layers by reinjection of the precursors, the nanosheets were not well-dispersed in solution. Yin et al. also developed a colloidal protocol to produce 1T'-WS2 nanosheets by one-pot synthesis. However, TEM and STEM images support the formation of 1T'-WS2 nanochains with 162 nm diameter assembled nanosheets. Son et al. developed a protocol to produce colloidal quantum dots of WS2, where they sonicated WS2 powders in an appropriate solvent, then separated the WS2 quantum dots. More recently, Liu et al. developed a comprehensive colloidal protocol to produce metallic phase nanosheets of MoS2, MoSe2, WS2, and WSe2. In the last step of the synthesis, they induced phase change by annealing the nanosheets under argon atmosphere at 500°C for 1 hour. TEM images show that the nanosheets are neither monodisperse nor colloidally stable. This last study does not yet fulfill the aforementioned demand for colloidally stable and size-controlled nanosheets of WS2. This paper presents a novel colloidal protocol to produce well-dispersed and size-controlled nano-monolayers (NMLs) of 1T'-WS2. We develop a colloidal synthesis protocol in which 1-octadecanethiol (ODT) is used as the tungsten coordinating agent, reducing its reactivity and allowing for a better synthetic control. We use different characterization techniques such as UV-Vis spectroscopy, powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), and small angle X-ray scattering (SAXS) to prove that the products of the synthesis are colloidally stable 1T'-WS2 monolayers. Additionally, Fourier transform infrared spectroscopy (FTIR), ligand exchange, and thermogravimetric analysis (TGA) are used to probe the nature of the NMLs surface ligands. Finally, we demonstrate control over the size of 1T'-WS2 NMLs by changing the amount of ODT as well as the reaction time, producing monodisperse NMLs with mean sizes ranging from 10 to 60 nm diameter. This high-yield reaction leads to the formation of the highest quality nano-monolayers that have been synthesized to date. We believe this new colloidal synthesis can spur the widespread study and use of colloidal TMDC nano-monolayers.