Compact multi-port power combiners and dividers with filter characteristics are introduced. These components advantageously combine the functions of power distribution and filtering in a single component, thus reducing the number of components in a system and improving overall system performance. The design principle, which is entirely based on filter theory, is first presented for a symmetric filtering four-port combiner/divider and is then extended to an eight-port network. Measurements on a symmetric all-metal waveguide four-port prototype show excellent agreement with simulations and validate the general design approach. The experimental response of an asymmetric substrate integrated waveguide eight-port network agrees reasonably well with simulations and demonstrates that the basic four-port element can be extended to very compact multi-port combiner/dividers to cope with a variety of systems requirements.