π-conjugated polymers hold considerable promise as key materials in various devices because of their advantageous optical, electronic, and magnetic properties; however, their strong inter-chain π–π interactions render them insoluble without the introduction of solubilizing substituents, making their synthesis highly challenging. Confined synthesis of π-conjugated polymers inside metal–organic frameworks (MOFs) offer a solution to this challenge by isolating the individual polymer chains, effectively addressing solubility issues and regulating polymerization reactions to yield novel π-conjugated polymers that are otherwise inaccessible. This account reviews recent advances in the synthesis and assembly control of π-conjugated polymers within MOFs to enhance physicochemical properties. Additionally, we explore the nanohybridization of π-conjugated polymers with MOFs, leading to sophisticated architectures with intriguing functionalities.