A work vehicle includes: a vehicle body frame; a prime mover part that is supported by the vehicle body frame; a bonnet that is configured to vertically swing between a closed position at which the prime mover part is covered, and an open position at which the prime mover part is open; and a support frame that supports a free end side of the bonnet located at the closed position. At least left and right guide-target parts of the bonnet or left and right guiding parts of the support frame have left and right inclined surfaces that serve as centering effective surfaces.