A road surface submergence estimation device comprising: an acceleration acquisition unit configured to acquire an actual acceleration of a vehicle; a torque acquisition unit configured to acquire an actual torque transmitted from a driving source to wheels of the vehicle, the driving source being mounted on the vehicle; and an estimation unit configured to determine whether a predetermined submergence determination condition is satisfied using the actual acceleration and the actual torque and, when it is determined that the submergence determination condition is satisfied, to estimate that a road surface on which the vehicle is traveling is submerged, the estimation unit being configured to determine that the submergence determination condition is satisfied at least when a condition that a first parameter is larger than a first threshold is satisfied, the first parameter being a parameter that increases as a difference between a first variable and a second variable increases, the first variable being a variable that increases as the actual acceleration increases, and the second variable being a variable that increases as the actual torque increases, wherein the first variable is the actual acceleration, the second variable is a theoretical acceleration that is an acceleration of the vehicle when the vehicle is traveling on a non-submerged, flat road surface, the theoretical acceleration being calculated based on the actual torque, and the first parameter is a product of a variance of acceleration difference values in a first predetermined duration and a current-time value of the acceleration difference value, the acceleration difference value being a difference between the theoretical acceleration and the actual acceleration. an acceleration acquisition unit configured to acquire an actual acceleration of a vehicle; a torque acquisition unit configured to acquire an actual torque transmitted from a driving source to wheels of the vehicle, the driving source being mounted on the vehicle; and an estimation unit configured to determine whether a predetermined submergence determination condition is satisfied using the actual acceleration and the actual torque and, when it is determined that the submergence determination condition is satisfied, to estimate that a road surface on which the vehicle is traveling is submerged, the estimation unit being configured to determine that the submergence determination condition is satisfied at least when a condition that a first parameter is larger than a first threshold is satisfied, the first parameter being a parameter that increases as a difference between a first variable and a second variable increases, the first variable being a variable that increases as the actual acceleration increases, and the second variable being a variable that increases as the actual torque increases, wherein the first variable is the actual acceleration, the second variable is a theoretical acceleration that is an acceleration of the vehicle when the vehicle is traveling on a non-submerged, flat road surface, the theoretical acceleration being calculated based on the actual torque, and the first parameter is a product of a variance of acceleration difference values in a first predetermined duration and a current-time value of the acceleration difference value, the acceleration difference value being a difference between the theoretical acceleration and the actual acceleration.