Non-noble transition metal oxides, particularly TiO2-based systems, can be an alternative to noble metal-based catalysts for the electrochemical ammonia oxidation reaction (AOR) due to their abundance, low cost, and corrosion resistance, but it remains hindered by lower performance and undesired selectivity toward oxygenated nitrogen species instead of N2, largely stemming from insufficient active sites and higher energy barrier for coupling intermediates. To overcome the issues, we introduce a Ni single-atom-induced covalent modulation strategy for constructing Ni SAC@TiO2 with tunable Ti-O covalency. Hard and soft X-ray absorption (XAS) combined with photoelectron spectroscopy (XPS) reveal strong metal-support interactions that enhance Ti-O covalency and create abundant active sites. Ni SAC@TiO2 catalyst nearly doubles the catalytic activity of pristine TiO2 and retains >98% of its initial performance after 2000 accelerated stress testing cycles. In situ surface-enhanced Raman scattering (SERS) shows improved interaction with reactants and intermediates, while in situ attenuated total reflection-surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) demonstrates that Ni SAC@TiO2 effectively suppresses the buildup of deactivating NOx species and promotes NHx-NHy coupling mediated pathways for selective N2 evolution, further corroborating the theoretical insights. These findings highlight single-atom modulation of Ti-O covalency as a powerful strategy to unlock efficient and robust TiO2-based catalysts for AOR.