There is a range of uses for groundwater and aquifers, mostly non-water supply uses, which have been termed ‘exotic’. These uses can be categorized into four distinct fields: fluid storage and waste disposal, including deep-well injection; energy conservation, including storage of fossil fuel-generated energy (as heat or pressure) and the extraction of solar energy from groundwater; subsurface in situ leaching of economic minerals; and groundwater quality management. Some details of each of these fields of application are presented to illustrate their essential multi-disciplinary nature and also the benefits that can arise from their use. Much more intensive investigation than normal is considered necessary to obtain the detailed site-specific data that any application would require. This would also have to be linked with an adequate regional monitoring system, which protects potable groundwater and other minerals. Possible applications in the United Kingdom are considered.