The design of new electrode materials with high redox stability has great potential for the fabrication of solid oxide fuel and electrolysis cells having a symmetrical configuration; such a configuration is particularly promising in terms of economic and technological factors due to involving a reduced number of functional materials and technological steps. Under the framework of the present study, we developed new Nd_1–xBa_xFe_0.9M_0.1O_3–δ materials (where M = Cu or Ni, x = 0.4 or 0.6), characterizing their functional properties (oxygen non-stoichiometry, thermomechanical and electrical properties) under both oxidizing and reducing conditions, as well as demonstrating the principal capability of their application as symmetrical electrodes in proton-conducting electrochemical cells. The obtained results demonstrate the desirability of a low barium content due to decreased thermal expansion coefficients and chemical strain contribution and Cu-doping due to the formation of an electrochemically active scaffold having nano-sized sediments. The Nd_0.6Ba_0.4Fe_0.9Cu_0.1O_3–δ electrodes fabricated onto the BaCe_0.5Zr_0.3Y_0.1Yb_0.1O_3–δ proton-conducting electrolytes exhibit polarization resistances of 1.1 and 15.1 Ω cm² at 600 °C in wet air and wet hydrogen measuring atmospheres, respectively. These reported results are among the first concerning the effective operation of symmetrical electrodes in systems with proton-conducting electrolytes. [Figure not available: see fulltext.].