Herein, we study the feasibility of using nanocellulose (NC)-based composites with silver and platinum nanoparticles as additive materials to fabricate the support layer of thin film composite (TFC) membranes for water purification applications. In brief, the NC surface was chemically modified and then was decorated with silver and platinum nanoparticles, respectively, by chemical reduction. These metalized nanocellulose composites (MNC) were characterized by several techniques including: FTIR, XPS, TGA, XRD, and XANES to probe their integrity. Thereafter, we fabricated the MNC-TFC membranes and the support layer was modified to improve the membrane properties. The membranes were thoroughly characterized, and the performance was evaluated in forward osmosis (FO) mode with various feed solutions: nanopure water, urea, and wastewater samples. The fabricated membranes exhibited finger-like pore morphologies and varying pore sizes. Interestingly, higher water fluxes and solute rejection was obtained with the MNC-TFC membranes with wastewater samples. The overall approach of this work provides an effort to fabricated membranes with high water flux and enhanced selectivity.