a tamper resistant faucet handle is provided for locking conventional sink or bath faucets in a closed or partially closed position . the tamper resistant faucet handle includes a handle body mounted to the flow control lever and a movable interference plunger that is slidably located within a plunger bore contained in the handle body . a locking mechanism locks the interference plunger in either an inward position or an outward position . when the interference plunger is locked in the outward position , it resides partially beyond the surface of the handle body for a distance sufficient for the plunger to interfere with movement of the handle body and consequently the flow control lever . in this manner , the locked plunger limits the range of movement of the flow control lever to lock the faucet in a closed or semi - closed position . the locking mechanism can be released and the plunger returned to the inward position , thus re - establishing a full range of movement for the handle and the flow control lever . an embodiment of the invention is disclosed for use on single control faucets , and another embodiment is disclosed for use on dual control faucets . the locking mechanism requires two - handed coordination , and is therefore childproof . the locking mechanism for both embodiments preferably includes an actuation button that can be removed to prevent unauthorized use of the faucet by children or adults .