Abstract: An arm steady rest provides support of the arm, particularly the forearm and/or wrist, of a person holding a relatively heavy or bulky article (e.g., rifle, archery bow, video camera, etc.). The arm rest is attachable to the belt or clothing of the user, or may be tied or strapped to the user, or used as a monopod resting upon another surface. The brace arm of the device telescopes, and moreover provides for axial motion of the two telescopes elements relative to one another while they are longitudinally locked at a fixed length. Adjustability is provided for both the upwardmost and downward/forwardmost positions of the brace arm while in the extended position. The device may be drawn from the downward or retracted position to the upwardly extended position and locked therein, or vice versa, with one simple motion of one hand; no additional manipulation of other components is required. Frictional security is provided to hold the brace arm in the downward position when not in use.