A series of novel soluble conjugated phosphorescent copolymers with tetraphenylporphyrin platinum(II) complexes inserted into the polymer main chain is synthesized through direct metalation of the metal-free polyfluorene-co-tetraphenylporphyrin copolymers with PtCl2 in benzonitrile. Chemical and photophysical characterization confirms that platinum(II) was successfully incorporated into metal-free porphyrin in the copolymer backbone. The PL decay studies indicate that polyfluorene-co-tetraphenylporphyrin platinum(II) (PFO−PtTPP) is a triplet emitter. EL emission from the fluorene segment was completely quenched for copolymers with PtTPP content as low as 0.5 mol %. The PFO−PtTPP copolymers emit deep red emission. The highest external quantum efficiency of the devices based on the platinum(II) complex PFO−PtTPP1 (1 mol % PtTPP in copolymer) was 0.43% with emission peaking at 676 nm.