There are realized a vehicle control device and an electronic control system with high reliability capable of safely shifting control even when an operation abnormality occurs in a sensor around a vehicle or an arithmetic block that processes sensor fusion. The vehicle control device includes a first arithmetic block which performs sensor fusion processing based on pieces of raw data output from a plurality of surrounding environment sensors, a second arithmetic block which performs sensor fusion processing based on pieces of object data generated by processing the pieces of raw data output from the plurality of surrounding environment sensors, and a third arithmetic block which diagnoses an output result of the first arithmetic block by using the output result of the first arithmetic block and an output result of the second arithmetic block.