An axle device for a work vehicle, comprising: a wheel drive case having: a front coupling portion and rear coupling portion: configured to pivot relative to each other about a rolling axis, the rolling axis extending along a front-back direction of a vehicle body of the work vehicle, in use, and configured to be arranged at a center portion of the wheel drive case with respect to a lateral direction of the vehicle body, in use; and an input shaft configured to transmit rotational power to a pair of right-left wheels of the work vehicle, wherein the center portion includes a front portion and a rear portion, either one of the front portion and rear portion is provided with the input shaft, and the front coupling portion and rear coupling portion protrude above the input shaft, with respect to a vertical direction in use, from the front portion and the rear portion, respectively; a pair of wheel supports arranged on each outer end of the wheel drive case with respect to the lateral direction of the vehicle body and configured to support a pair of wheels for steering and pivoting; and a steering cylinder configured to steer the pair of wheel supports, the steering cylinder being supported by the wheel drive case to be located: below one of the front and rear coupling portions (15, 16) which is not provided with the input shaft, and within a width of the center portion of the wheel drive case with respect to the vertical direction, in use. a wheel drive case having: a front coupling portion and rear coupling portion: configured to pivot relative to each other about a rolling axis, the rolling axis extending along a front-back direction of a vehicle body of the work vehicle, in use, and configured to be arranged at a center portion of the wheel drive case with respect to a lateral direction of the vehicle body, in use; and an input shaft configured to transmit rotational power to a pair of right-left wheels of the work vehicle, wherein the center portion includes a front portion and a rear portion, either one of the front portion and rear portion is provided with the input shaft, and the front coupling portion and rear coupling portion protrude above the input shaft, with respect to a vertical direction in use, from the front portion and the rear portion, respectively; a front coupling portion and rear coupling portion: configured to pivot relative to each other about a rolling axis, the rolling axis extending along a front-back direction of a vehicle body of the work vehicle, in use, and configured to be arranged at a center portion of the wheel drive case with respect to a lateral direction of the vehicle body, in use; and configured to pivot relative to each other about a rolling axis, the rolling axis extending along a front-back direction of a vehicle body of the work vehicle, in use, and configured to be arranged at a center portion of the wheel drive case with respect to a lateral direction of the vehicle body, in use; and an input shaft configured to transmit rotational power to a pair of right-left wheels of the work vehicle, wherein the center portion includes a front portion and a rear portion, either one of the front portion and rear portion is provided with the input shaft, and the front coupling portion and rear coupling portion protrude above the input shaft, with respect to a vertical direction in use, from the front portion and the rear portion, respectively; a pair of wheel supports arranged on each outer end of the wheel drive case with respect to the lateral direction of the vehicle body and configured to support a pair of wheels for steering and pivoting; and a steering cylinder configured to steer the pair of wheel supports, the steering cylinder being supported by the wheel drive case to be located: below one of the front and rear coupling portions (15, 16) which is not provided with the input shaft, and within a width of the center portion of the wheel drive case with respect to the vertical direction, in use. below one of the front and rear coupling portions (15, 16) which is not provided with the input shaft, and within a width of the center portion of the wheel drive case with respect to the vertical direction, in use.