A modular frame for a backpack sprayer system includes a frame plate having a front surface, a back surface and first and second side edges. A first receiving channel is located along the first side edge and a second receiving channel is located along the second side edge. A support member has a first arm which is received within the first receiving channel and a second arm which is received within the second receiving channel. A stand portion extends at an angle relative to the first and second arms. A mounting member is coupled to the front surface of the frame plate and mounts a tank and a pump unit thereon. The mounting member includes opposing left and right sides, a planar top face and a front face including a concave portion to receive at least a portion of one or both of the tank and the pump unit.
