To provide an outrigger of a working vehicle that can secure a required overhang dimension of a grounding plate while preventing disturbance of a ground contact surface by the grounding plate without enlarging the width direction dimension of the vehicle.

The outrigger of the working vehicle includes: a hydraulic cylinder 2 in which an end of a rod part 2b is swingably connected with a bracket 1; a first link member 4 of which one end side is swingably connected to a cylinder part 2a of the hydraulic cylinder 2; and a second link member 5 and a third link member 6 whose one end sides are swingably connected to the first link member 4, and the other end sides are swingably connected to the bracket 1. Thereby, when elongating the hydraulic cylinder 2 from all shortened states, after moving the grounding plate 3 to outer side in width direction of the vehicle, while moving it downward by first to third link members 4, 5, and 6, movement to downward in an almost vertical direction becomes possible near the ground contact surface G, and the required overhang dimension of the grounding plate 3 can be secured while preventing disturbance of ground contact surface G by grounding plate 3, without enlarging the vehicle dimension in the width direction.