A sensor delay time estimation device that includes: a memory; and a processor coupled to the memory, wherein the processor is configured to: acquire an observable required to estimate a vehicle state from a plurality of sensors that detect and output the observable, each of the plurality of sensors being different, and based on the observable for a fixed time interval acquired from each of the plurality of sensors, estimate a time delay from detection to acquisition of the observable for each of the plurality of sensors, and estimate a vehicle state for the fixed time interval.