A liquid discharge apparatus includes a head, a recovery tank, a supply tank connected to the recovery tank, and a pressure regulator. The pressure regulator includes a first cylinder connected to an upper portion of the recovery tank, a first piston movable in the first cylinder, a first valve configured to open and close a path between the recovery tank and the first cylinder, depending on a position of the first piston, a second cylinder connected to the first cylinder and an upper portion of the supply tank, a second piston movable in the second cylinder, a second valve configured to open and close a path between the supply tank and the second cylinder, depending on a position of the second piston, and a third valve configured to open and close a path between the second cylinder and an atmosphere, depending on a position of the second piston.