Lawrence Livermore National Laboratory (LLNL) will be hosting a Workshop on Microwave Cavity Design for Axion Detection at the Livermore Valley Open Campus August 25-27th. Discovering the nature of dark matter is one of the major research efforts for DOE High Energy Physics. Primordial axion particles are a primary dark matter candidate and the most sensitive search techniques use resonant microwave cavities to convert the axions into detectable photons. These cavities are highly specialized and must operate in large magnetic fields at ultra-low temperatures. This workshop focuses on variety of unique design issues for these microwave cavities which include, but not limited to, developing high fidelity electromagnetic modeling, solving issues of cavity mode localization, construction techniques and materials, etc. The workshop is intended to draw in subject matter experts from both LLNL as well as SLAC, LBNL, Fermilab, U. of Washington, U. of Florida, U.C. Berkeley and others who are knowledgeable in axion searches, accelerator cavities and low temperature techniques. This workshop will be used to introduce researchers to the unique requirements of designing microwave cavities for axion searches as well as to develop new cavity systems that can extend searches for axion masses into currently inaccessible ranges. Though the workshop focuses on cavities for axion searches the cavity designs could have other applications such as accelerators or quantum information research. This workshop is supported by LLNL, the U. of Washington, and through a generous contribution from the Heising-Simons Foundation.