In tackling energy-related challenges in Nigeria; the exploration of an alternative source of energy (Geothermal Energy) comes to the limelight as it is generated below the earth subsurface. This work focuses on the delineation of geothermal energy potentials in parts of Calabar Flank, in southeastern Nigeria using Aeromagnetic Data. The aim is to understand the geothermal energy potentials and structural of parts of the Calabar flank by studying the various geothermal, geological, and structural parameters using Aeromagnetic Data. The methodologies applied are quantitative for structural analysis and qualitative using spectral analysis and 3D Euler Deconvolution. The study area lies between within Latitude 5°30ʹ00ʺ N - 6°30ʹ00ʺN and Longitude 7°30ʹ00ʺE - 8°30ʹ0ʺE respectively. Results from the 3D Euler analysis revealed the depth range of 0.25 Km to 4.018 Km. the spectral Analysis revealed a depth range of Magnetic source (Zt) is (-)0.564 Km to (-)0.828 Km, the Zo is (-)4.261 Km to (-)5.999 Km and the average depth to basement thickness is (-)4.825 Km. The Curie Point Depth, Geothermal Gradient, and Heat flow yield an average depth of (-)9.452 Km, a value of 61.893 °CKm-1, and 154.983 mWm-2 from the Spectral Analysis. Some structural features such as trending faults, and fractured basements was observed at the NE-SW of the study area and this correlated to the relatively high heat flow and geothermal gradient at the NNE-SSW part is associated with thermal structures, mineralogical and tectonic history from the NE-SW trending fault in the study area is suitable for geothermal energy exploitation.