A fluid-cooled stator assembly for electrical machines. The stator assembly may include a stator core having a back iron portion and a plurality of stator teeth. Each of the plurality of stator teeth may be separated from each other by at least one of plurality of slots, the slots being structured to receive placement of stator windings. The apparatus also includes a thermal management conduit that is positioned at various locations about the stator assembly, including within or along the back iron portion, stator teeth, slots, and/or among the stator windings. Further, the thermal management conduit may provide insulation for one or more coils of the stator windings. Additionally, at least a portion of the thermal management conduit may be formed from a thermally conductive polymer. The thermal management conduit is configured to convey a thermal management fluid in a heat exchange relationship with the stator assembly.