A monolever operation apparatus for a working vehicle, which improves operability with excellent fine operability of a monolever. For this purpose, the monolever operation apparatus for the working vehicle includes an arm rest provided at a console placed on at least either one of the left and right sides of an operator's seat, and a monolever which is placed in front of the arm rest and is rotatively operated in a fore-and-aft direction and in a left and right direction. When operated in the left and right direction, the monolever is allowed to be operated with a distance, from a fulcrum of operation below the operator's elbow placed on the arm rest up to a grip of the monolever, remaining almost constant.