A leaning vehicle (10, 10A, 10B, 10C) with a left-right pair of wheels (14FL, 14FR), comprising: a leaning vehicle body that is configured to lean in a vehicle's leftward direction when the leaning vehicle (10, 10A, 10B, 10C) is turning left and to lean in a vehicle's rightward direction when the leaning vehicle (10, 10A, 10B, 10C) is turning right; a plurality of wheels including a left-right pair of wheels (14FL, 14FR) that are arranged side by side in a vehicle's left-right direction, the plurality of wheels including one or two steerable front wheels that are supported by the leaning vehicle body in such a manner so as to be able to swivel around a steering axis extending in a vehicle body's up-down direction (ud), and one or two rear wheels that are supported by the leaning vehicle body, the number of the rear wheels being two when the number of the steerable front wheels is one, the number of the rear wheels being one or two when the number of the steerable front wheels is two, and the left-right pair of wheels (14FL, 14FR) being two steerable front wheels that are arranged side by side in the vehicle's left-right direction or being two rear wheels that are arranged side by side in the vehicle's left-right direction; a suspension mechanism configured to support the left-right pair of wheels (14FL, 14FR) in such a manner that the left-right pair of wheels (14FL, 14FR) is movable in the vehicle body's up-down direction (ud) relative to the leaning vehicle body; a steering mechanism configured to apply torque to the one or two steerable front wheels to swivel the one or two steerable front wheels around the steering axis; and a steering controller that is configured to control the steering mechanism, characterised in that the leaning vehicle (10, 10A, 10B, 10C) further comprises an up-down direction acceleration detector that is attached to the leaning vehicle body or the suspension mechanism to detect an acceleration in a vehicle's up-down direction or a vehicle body's up-down direction (ud), the up-down direction acceleration detector being capable of detecting an acceleration in the vehicle's up-down direction or the vehicle body's up-down direction (ud) generated as one of the left-right pair of wheels (14FL, 14FR) passes over a bump or pothole in the road; and the steering controller is configured to control the one or two steerable front wheels in such a manner that the one or two steerable front wheels are in a free-steering state, so as to be able to swivel around the steering axis freely, based on the acceleration generated in the vehicle's up-down direction or the vehicle body's up-down direction (ud) and detected by the up-down direction acceleration detector, as one of the left-right pair of wheels (14FL, 14FR) passes over a bump or pothole in the road. a leaning vehicle body that is configured to lean in a vehicle's leftward direction when the leaning vehicle (10, 10A, 10B, 10C) is turning left and to lean in a vehicle's rightward direction when the leaning vehicle (10, 10A, 10B, 10C) is turning right; a plurality of wheels including a left-right pair of wheels (14FL, 14FR) that are arranged side by side in a vehicle's left-right direction, the plurality of wheels including one or two steerable front wheels that are supported by the leaning vehicle body in such a manner so as to be able to swivel around a steering axis extending in a vehicle body's up-down direction (ud), and one or two rear wheels that are supported by the leaning vehicle body, the number of the rear wheels being two when the number of the steerable front wheels is one, the number of the rear wheels being one or two when the number of the steerable front wheels is two, and the left-right pair of wheels (14FL, 14FR) being two steerable front wheels that are arranged side by side in the vehicle's left-right direction or being two rear wheels that are arranged side by side in the vehicle's left-right direction; a suspension mechanism configured to support the left-right pair of wheels (14FL, 14FR) in such a manner that the left-right pair of wheels (14FL, 14FR) is movable in the vehicle body's up-down direction (ud) relative to the leaning vehicle body; a steering mechanism configured to apply torque to the one or two steerable front wheels to swivel the one or two steerable front wheels around the steering axis; and a steering controller that is configured to control the steering mechanism, characterised in that the leaning vehicle (10, 10A, 10B, 10C) further comprises an up-down direction acceleration detector that is attached to the leaning vehicle body or the suspension mechanism to detect an acceleration in a vehicle's up-down direction or a vehicle body's up-down direction (ud), the up-down direction acceleration detector being capable of detecting an acceleration in the vehicle's up-down direction or the vehicle body's up-down direction (ud) generated as one of the left-right pair of wheels (14FL, 14FR) passes over a bump or pothole in the road; and the steering controller is configured to control the one or two steerable front wheels in such a manner that the one or two steerable front wheels are in a free-steering state, so as to be able to swivel around the steering axis freely, based on the acceleration generated in the vehicle's up-down direction or the vehicle body's up-down direction (ud) and detected by the up-down direction acceleration detector, as one of the left-right pair of wheels (14FL, 14FR) passes over a bump or pothole in the road.