Mode conversion processes in plasmas allow wave energy to transferred between two or more different wave modes, and are often invoked in theories of space and astrophysical phenomena. For instance, electrostatic Langmuir waves which are trapped in the solar wind plasma can be converted to electromagnetic radiation and produce radio bursts, which can propagate through the plasma and thus be observed remotely. In environments where mode conversion has been invoked there is often a significant ambient magnetic field. This modifies the dispersion relations of the wave modes and can result in additional wave modes. However, magnetization effects have been neglected in the analyses of certain mode conversion processes. This thesis presents a number of investigations into mode conversion processes as they occur in magnetized plasmas, focusing on the magnetization of the Langmuir mode