Silylene- and siloxane-containing conjugated polymers and macrocycles were synthesized by acyclic diene metathesis (ADMET), starting from diene-functional monomers. In the case of silylene, linear polycondensates were observed, whereas the siloxane cases resulted in cyclic condensates. The presented systems highlight the ring-chain equilibrium inherent in ADMET reactions, and significantly expand the synthetic scope of ADMET chemistry to novel heteroatom containing polymeric systems.