Geological studies indicate that one of the most important geothermal systems of Turkey is located in the western Anatolia. There are plenty of studies covering the geological, geophysical and modeling aspects on land. In this study, for the first time, we construct coupled numerical models of fluid flow and temperature offshore Gulf of Izmir and Seferihisar-Doanbey, using constraints from marine seismic data, which reveal pockmarks, mud volcanoes, and fluid vents. The numerical models were designed by taking into account of main tectonic structures such as Izmir Fault, Doanbey Fault, Tuzla Fault and Seferihisar Horst. It is found that hydrothermal circulation pattern is influenced by the combination of presence of faults, sediment thickness and seafloor bathymetry. The models here give new insights into the future studies on the possible fluid transport mechanisms.