An overview of the electrochemistry of poly(3,4‐alkylenedioxythiophene)s (PXDOTs) is presented. As a class of conducting and electroactive polymers that can exhibit high and quite stable conductivities, a high degree of optical transparency as a conductor, and the ability to be rapidly switched between conducting doped and insulating neutral states, PXDOTs have attracted attention across academia and industry. Numerous fundamental aspects are addressed here in detail, ranging from the electrochemical synthesis of PXDOTs, a variety of in‐situ characterization techniques, the broad array of properties accessible, and morphological aspects. Finally, two electrochemically‐driven applications, specifically electrochromism and chemical sensors of PXDOTs are discussed.