Abstract: Metal cocatalysts are commonly incorporated into conjugated polymer photocatalysts to provide catalytic centers for hydrogen evolution. However, conventional cocatalyst integration provides limited control over charge-transfer pathways between photoactive conjugated backbones and catalytic centers. Here, we develop cycloplatinated conjugated polymer dots (Pdots) in which the molecular connectivity of catalytic Pt centers is engineered to control whether the π-conjugated pathway passes through or bypasses the Pt center. Combined theoretical calculations and experimental studies indicate that through-Pt connectivity facilitates charge transfer to the catalytic Pt center. PFTBTA–PtPy₂ Pdots, in which the π-conjugated pathway passes through the catalytic Pt center, exhibit a 10.6-fold enhancement in photocatalytic hydrogen evolution compared with the bypass-Pt analogue, underscoring the critical role of molecular Pt connectivity in photocatalytic performance. Furthermore, colloidal stabilization suppresses nanoparticle aggregation, enabling stable photocatalytic hydrogen evolution for over 45 h under continuous irradiation while preventing the rapid deactivation observed in the unstabilized system. These findings highlight molecular control over Pt center positioning and colloidal stabilization as complementary design strategies for regulating charge-transfer pathways and achieving efficient and durable conjugated polymer photocatalysis.