In this work, the local structure of the acceptor Ba1+хLa1–хInO4–0.5х and donor BaLaIn1–хTiхO4+0.5х doped solid solutions based on BaLaInO4 was investigated. The appearance of new types of the defects (oxygen vacancy and oxygen interstitial) in the crystal lattice was confirmed by the spectroscopic investigations. It was shown that for both solid solutions the same tendency of the increase in the symmetry of the structure and the expansion of interlayer space with increasing dopant concentration is observed. The changes in the transport properties (ionic conductivity) have the same tendency for both solid solutions. The increase in the oxygen‐ionic and protonic conductivity in the area of “low” dopant concentrations (x < 0.05) is due to the increase in the mobility of ions caused by the influence of geometric factor. The decrease in the ionic conductivity values in the area of “high” dopant concentrations (x > 0.05) is caused by the appearance of interaction between defects (concentration factor). The most conductive ionic (oxygen‐ionic and protonic) material with Ruddlesden–Popper (RP) structure based on BaLaInO4 is Ba1.1La0.9InO3.95 composition.