Three-dimensional (3D) analysis was carried out for oxygen transport in silicon melts of a Czochralski (CZ) growth process with electromagnetic fields. The system with electromagnetic fields was established with a transverse magnetic field and an injected electric current applied on the melt surface. The melt flow and thermal field in the growth furnace were numerically obtained with a recently developed 3D global model. The influence of electrode position and electric current direction on the oxygen distribution and concentration in the melt as well as on the growth interface was investigated. The heat transfer and mass transfer in the melt were also analyzed to clarify the mechanisms. The results showed that control of the oxygen distribution and concentration on the crystal growth interface is possible by appropriate positioning of the electrode on the melt surface and appropriate selection of the electric current direction. The results also showed that an electromagnetic CZ process (EMCZ) is superior to a transverse magnetic field-applied CZ process (TMCZ) and a conventional CZ process for controlling oxygen distribution in a silicon crystal grown from melt.