Coastal marshes are highly dynamic and ecologically important ecosystems that are subject to pervasive and often harmful disturbances, including shoreline erosion. Shoreline erosion can result in an overall loss of coastal marsh, particularly in estuaries with moderate- or high-wave energy. Not only can waves be important physical drivers of shoreline change they can also influence shore-proximal vertical accretion through sediment delivery. For these reasons, estimates of wave energy can provide a quantitative measure of wave effects on marsh shorelines. Since wave energy is difficult to measure at all locations, scientists and managers often rely on hydrodynamic models to estimate wave properties at different locations. The Wave Exposure Model (WEMo) is a simple tool that uses linear wave theory to estimate wave energy characteristics for enclosed and semi-enclosed estuaries (Malhotra and Fonseca, 2007). The interpretation of hydrodynamic models is improved if model results can be validated against measured data. The data presented in this publication are input and validation data for modeled and observed mean wave height for two temporary oceanographic stations established by the U.S. Geological Survey (USGS) in the Grand Bay National Estuarine Research Reserve, Mississippi.