Devices, systems, and methods for modular molding of wind turbine blades are provided. Methods of molding wind turbine blades using a modular molding assembly or system and methods of substituting molds are provided. In some embodiments, a modular assembly includes a first base frame and a second base frame hingedly coupled to one another, a first tooling frame disposed on the first base frame, a second tooling frame disposed on the second base frame, a first shell mold coupled to the first tooling frame, and a second shell mold coupled to the second tooling frame. The first shell mold has a first mold surface and a first perimeter and the second shell mold has a second mold surface and a second perimeter. When in an open configuration, the first base frame is coplanar with the second base frame, and, in a closed configuration, the first perimeter contacts the second perimeter.