A new series of cobalt‐free perovskite‐type oxides, Nd0.5Ba0.5Fe1–xNixO3–δ (0 ≤ x ≤ 0.15), have been prepared by a citric acid‐nitrate process and investigated as cathode materials for proton conducting intermediate temperature solid oxide fuel cells (IT‐SOFCs). The conductivity of the oxides was measured at 300–800 °C in air. It is discovered that partial substitution of Ni for Fe‐sites in Nd0.5Ba0.5Fe1–xNixO3–δ obviously enhances the conductivity of the oxides. Among the series of oxides, the Nd0.5Ba0.5Fe0.9Ni0.1O3–δ (NBFNi10) exhibits the highest conductivity of 140 S cm−1 in air at 550 °C. A single H2/air fuel cell with proton‐conducting BaZr0.1Ce0.7Y0.2O3–δ (BZCY) electrolyte membrane (ca. 40 μm thickness) and NBFNi10‐BZCY composite cathode and NiO‐BZCY composite anode was fabricated and tested at 600–700 °C. The peak power density and the interfacial polarization resistance (Rp) of the cell are 490 mW cm−2 and 0.15 Ω cm2 at 700 °C, respectively. The experimental results indicate that NBFNi10 is a promising cathode material for the proton‐conducting IT‐SOFCs.