Ba3MoNb1-xGaxO8.5-δ　(BMNG,　0　≤　x　≤　0.2)　powders　are　successfully　prepared　by　sol-gel　autoignition　method.　The　effects　of　acceptor-type　Ga3+　doping　on　Ba3MoNbO8.5　(BMN)　are　characterized　by　thermogravimetric　analysis,　X-ray　diffraction,　scanning　electron　microscope,　Raman　spectroscopy,　and　electrochemical　impedance　spectroscopy.　All　BMNG　samples　crystallize　as　a　single　phase　in　the　R-3m　space　group　and　show　great　phase　stability　at　various　environments.　Doping　a　small　amount　of　gallium　can　effectively　improve　bulk　conductivity　and　sintering　density　of　BMN.　The　ionic　conductivity　of　Ba3MoNb0.9Ga0.1O8.5-δ　(BMNG10)　is　the　highest,　which　can　reach　2.05　×　10−2　S　cm−1　at　800　°C.　The　enhanced　ionic　conductivity　is　primarily　related　to　the　increase　of　oxygen　vacancy　concentration　and　the　number　of　tetrahedral　units　within　the　structure.　In　addition,　through　successfully　assembling　and　evaluating　a　single　cell　supported　by　the　BMNG10　electrolyte,　it　is　proved　that　the　practical　utilization　of　BMNG10　in　intermediate　temperature-solid　oxide　fuel　cells　(IT-SOFCs)　is　feasible.　In　short,　hexagonal　perovskite　derivative　BMNG10　is　a　promising　oxide　ion　conductor　for　IT-SOFCs.　©　2021　Elsevier　Ltd　and　Techna　Group　S.r.l.