A tri-position hairbrush includes a modular bristle-bed, having a plurality of bristles connected thereto; and a handle, connected to the modular bristle-bed. A switching unit operates to switch and convert the modular bristle-bed among three operational states. In a first operational state, which is a Closed State, the modular bristle-bed is arranged as a cylindrical structure that spans 330 to 360 degrees of curvature, and the hairbrush operates a round hairbrush. In a second operational state, which is a Semi-Open State, the modular bristle-bed is arranged as a curved cylinder-portion of 150 to 210 degrees of curvature, and the hairbrush operates as an open-curve hairbrush. In a third operational state, which is a Fully-Open State, the modular bristle-bed is arranged as a generally-flat surface, and the hairbrush operates as a paddle hairbrush.