High-entropy perovskites (HEPs) are attracting increasing attention as air electrode materials for solid oxide cells (SOCs). In this work, three different HEPs from the series La _0.2Pr _0.2Nd _0.2Sm _0.2Sr _0.2Co _1-xFe _xO _3-δ (x = 0, 0.5, 1) are synthesized using the citric acid-ethylenediaminetetraacetate (EDTA) method. X-ray diffraction analysis finds crystal structures with the orthorhombic space group 62 (Pnma) at room temperature. The lattice distortion increases with increased Fe-substitution at the B-site. The electrical conductivity (σ _e) is determined at temperatures from 600 to 850 °C and oxygen partial pressures (pO ₂) between 0.001 and 0.15 bar. For the pure cobaltate, σ _e is 1469 S cm ⁻¹ at 800 °C and 0.15 bar pO ₂. The conductivity is significantly reduced with Fe-doping, reaching 87 S cm ⁻¹ for the pure ferrate at 800 °C. The chemical oxygen surface exchange coefficient (k _chem) and the chemical oxygen diffusion coefficient (D _chem) are determined by the electrical conductivity relaxation technique. D _chem is found to be quite independent of B-site doping and pO ₂, with values of approx. 5 × 10 ⁻⁶ cm ² s ⁻¹ at 800 °C. In contrast, k _chem is strongly influenced by the B-site composition, which results in an increase of more than one order of magnitude from the ferrate (3.4 × 10 ⁻⁵ cm s ⁻¹) to the cobaltate (7.7 × 10 ⁻⁴ cm s ⁻¹) at 800 °C and 0.001 bar pO ₂. This clearly demonstrates the beneficial effects of Co on the electronic conductivity as well as on the catalytic activity for the oxygen surface exchange reaction.