Experimental searches for forces beyond gravity and electromagnetism at sub-millimeter length scales have attracted renewed attention in recent decades, yet there could be forces of nature many orders of magnitude stronger than gravity acting below this range for which there is no evidence.  Predictions of exotic, short-range forces arise in many models that attempt to describe gravity and the other known interactions in the same theoretical framework.  Such forces could be mediated by dark matter and dark energy, the otherwise unknown quantities thought to make up 95% of the density of the known universe.  I describe experiments sensitive to mass-coupled and spin-coupled forces, focusing on experiments using macroscopic test masses and some using nuclear techniques.  The sensitivity of these experiments is projected to cover much of the parameter space for exotic interactions in the range of interest.