The geothermal gradient in the Calgary area of southern Alberta is about 24°C/km. Although this is only an average geothermal gradient, the city lies on the flank of a deep portion of the western Canadian basin with sediment thickness of over 4 km so that a wide temperature range exists in the sediments. This factor, and the substantial population of the city and surrounding area, satisfy two prerequisites for successful recovery and use of low-grade geothermal energy. The Calgary area is, therefore, a suitable candidate for an investigation of its geothermal energy potential. The results of a study of petroleum exploration data show that good aquifers exist in the carbonate rocks of the Elkton formation of the Mississippian and the Wabamun formation of the Upper Devonian. The water temperatures range from 60°C to 90°C with salinities of 70 000 to 100 000 mg/l, which is two to three times that of average sea water. High water flow rates up to 700m3/hr from the Elkton formation at moderate depths may be obtained in areas northwest and south of the city. Although the flow rates for the Wabamun formation are lower, the Wabamun and the deeper Leduc formations could supplement the Elkton as the main target for geothermal purposes. The availability of hot water of reasonable quality and at reasonable depth, together with the large population, means that Calgary presents an attractive location for geothermal energy recovery and use.