The effect of Ca2+ − doping on the electrical conductivity of the oxide BaLa2In2O7 with Ruddlesden-Popper structure was investigated for the first time. The BaCaxLa2-xIn2O7-0.5× solid solution exists in the composition range of 0 ≤ x ≤ 0.10. The electrical conductivity of the BaCaxLa2-xIn2O7-0.5× ceramic samples was measured as a function of temperature (T), oxygen partial pressure (pO2), and water vapor partial pressure (pH2O). The introduction of Ca2+ into the crystal lattice led to an increase in oxygen-ion conductivity by 0.25 orders of magnitude at 500 °C, which is attributed to the formation of oxygen vacancies. The share of oxygen-ion transport increased from 23 to 80% with decreasing temperature from 900 to 425 °C, compared to 20% for the undoped phase for the same temperature range. The increase in pH2O increases the proton concentration in the structure, which is confirmed by the growth of conductivity and the reduction in activation energy. The activation energy of proton conduction increases with increasing x due to additional contribution of the proton «trapping» energies ΔEH. The doped BaCaxLa2-xIn2O7-0.5× samples are nearly pure protonic conductors below 600 °C, but undoped sample exhibits predominant proton transport below 300 °C. The electrical properties of BaMxLa2-xIn2O7-0.5x (M = Ca2+, Sr2+, and Ba2+) were compared.