The past decade has witnessed a visual explosion in the discovery of high-performance semiconducting polymers. A few representative materials among them have been subjected to the evaluation of their applicability in daily use. Although many design concepts have been extracted from a diverse array of such polymers, the structural aspects are still evolving and continue to fuel the development of flexible electronics. Among the newly developed systems, quinoid-containing polymers have shown promise in low-gap semiconductors as novel electronic materials. This review provides an overview of the recent progress in quinoidal polymer semiconductors for use in electronics, focusing on the construction of these quinoidal frameworks and their interesting electronic structures. We discuss the origin of the narrow gap and how this feature is appropriately leveraged to meet the requirements of high-mobility materials design. Also included is the derivatization for analog preparation to disclose the chemical space of such quinoid-based polymers.