A new generation of soluble phenothiazinyl merocyanine substituted polyacetylenes can be readily synthesized by rhodium‐catalyzed polymerization of the corresponding 3‐ethynyl phenothiazines, accessible by Sonogashira coupling and Knoevenagel condensation. UV/Vis and fluorescence spectroscopy of 7‐acceptor‐substituted phenothiazinyl polyacetylenes reveal that these polyacetylenes with conjugatively ligated merocyanines are luminescent in solution with positive emission solvatochromism and, in some cases, with distinct solid‐state luminescence.