An improved waveguide isolator that eliminates the transitions to air-filled waveguides between ferrite elements and absorptive load elements is described. The waveguide isolator in accordance with the invention can be implemented in variations from a single ferrite to load transformer held in close proximity to an absorptive load element to any number of ferrite elements and absorptive load elements as required to achieve the desired isolation performance or to create a switch matrix with any combination of input and output ports. The waveguide isolator in accordance with the invention eliminates the transitions between ferrite to load transformers and absorptive load elements and thus reduces component size and mass.