A multifunctional chair includes a support body, a telescopic structure, a seat body and a pedal assembly. The pedal assembly includes a fixing rod, a movable rod, an operating element and an elastic resistance element. The telescopic structure is connected with the support body, and the telescopic structure can be operated to move telescopically relative to the support body. One end of the fixing rod is fixed to the support body. The movable rod is movably connected with the fixing rod. The operating element is located at the end of the movable rod. Two ends of the elastic resistance element are respectively connected to the support body and the fixing rod. When the movable rod and the fixing rod are rotated toward the ground by pressing the operating element, the elastic resistance element can provide elastic resistance accordingly, so that the user can perform related muscle training exercises.