For long-term fuel cell application, the fabrication of a high-conductive and chemically durable sulfonated aromatic proton exchange membrane (PEM) is the most demanding requirement. Herein, we have synthesized a new series of phosphine oxide and pyridinyl moieties-based aromatic sulfonated polytriazoles (SPTs) with high ion exchange capacity values (IEC _w: 1.84–3.13 meqiv/g). The chemical structures of the PFPYSNa-XX copolymers are confirmed by various spectroscopy techniques. The inherent viscosity values (η _inh: 1.34–1.54 dL/g) and size exclusion chromatography results (SEC; weight-average molecular weight: 72–260 kDa, polydispersity index: 1.65–2.39) of the copolymers indicate the formation of high molecular weight SPTs by the “Click” polymerization reaction. The PFPYSH-XX polymers demonstrate excellent thermal stability (T _d5%: 250-294 °C) and appropriate mechanical properties. The fabricated PFPYSH-XX copolymer membranes reveal an inter-connected hydrophobic-hydrophilic phase-segregated morphology in various morphological investigations. Despite the high IEC values, the PFPYSH-XX membranes display better oxidative stability than the literature-reported analogous SPT membranes (τ ≥ 22 h). Also, all copolymers possess high residual weight (>94 %), and no cracks or pinholes are produced after an hour of Fenton's test at 80 ^°C. The PFPYSH-XX membranes exhibit exceptionally high proton conductivity (σ: 60–206 mS/cm at 80 ^°C), even higher than that of Nafion-117.