A polyaryleneether has been synthesized from bis‐(4‐cholorophenyl)di‐acetal (DPDA) monomer with bisphenol A and allyl bisphenol‐A. The copolymer was then functionalized with 2‐acrylamide‐2‐methyl propane sulfonic acid through radical grafting (SPAE/DPDA). The successfully synthesized SPAE/DPDA polymer was validated by using FTIR and NMR. Secondly, a composite nanostructure of MoS2/GNS nanosheet has been prepared and characterized using PXRD, FE‐SEM, and HR‐TEM. The composite membrane casted with SPAE/DPDA and varying weight percentage of 1%, 2%, 3%, 5%, 7%, and 10% MoS2/GNS nanosheet, has been characterized for ion exchange capacity (IEC), water stability (WU), swelling properties (SR), oxidative stability, and proton conductivity (PC).The MoS2/GNS dispersed SPAE/DPDA polymer nanocomposites membrane showed a chemical degradation of 22.56% and proton conductivity (PC) of 2.5 × 10−2 S/cm at 110°C. The results show that these membranes have high proton conductivity and can be used in proton exchange membrane fuel cells (HT‐PEMFCs).