It's alive: A ring‐strained alkyne based on dibenzo[a,e][8]annulene undergoes ring‐opening metathesis polymerization (ROMP) to give a high‐molecular‐weight poly(ortho‐phenylene) featuring alternating ethyl and ethynyl linkers along the polymer backbone. The molybdenum‐alkylidyne‐based catalyst system discriminates between strained and unstrained alkynes to yield a living polymer with an unparalleled