Thermal oil recovery is typically used to recover heavy oil and bitumen. It involves raising the temperature of oil to dramatically reduce its viscosity. During this process, the temperature distribution is an important factor. Conventional thermal methods, such as steam injection, may not be effective for deep wells or thin zones. An alternative thermal process is electromagnetic heating. At present, there are no commercial tools that include electromagnetic heating in reservoir simulators and there are no models for full coupling of electromagnetic heating and multiphase flow. This dissertation sets out to develop an EM heating model that couples the fluid flow and thermal responses of a reservoir when an EM source is applied around a wellbore. Numerical solutions are obtained due to the complexity of the fluid flow and EM equations and their system. This model presents a two-phase, three-dimensional model that simulates the water and oil flow in a reservoir. The temperature distribution and improved oil recovery from electromagnetic heating are calculated when multiple phases are present. Case studies are presented to show the accuracy and applicability of the model.