Herein, we report a detailed investigation of efficient hybrid photocatalyst system for carbon dioxide reduction. The system is based on a co-assembly of conjugated polymer photosensitizer (P3HT) and molecular Re(I) reduction catalyst on TiO2 semiconductor. The hybrid system consists of P3HT (poly(3-hexylthiophene-2,5-diyl)) as a visible-light photosensitizer and fac-[Re(4,4′-bis(methylphosphonic acid)-2,2′-bipyridine)(CO)3Cl] as a CO2 reduction catalyst (ReP). The P3HT photosensitizer is coated onto Re(I) catalyst (ReP)-loaded TiO2 particles to build up a new polymer-sensitized TiO2 photocatalyst system (P3HT/TiO2/ReP). The P3HT-based hybrid system showed the most durable catalytic activities compared to our previous ternary systems using molecular photosensitizer. Under irradiation with low energy light (＞500 nm), the hybrid P3HT/TiO2/ReP catalyst showed a TON of ~5300 over an extended time period of 830 h.