<p>In electrochemistry, ions and electrons move together to carry charge and drive chemical reactions, which has resulted in the innovation of many technologies, such as energy storage batteries, biosensors, and fuel cells. Organic electrochemical transistors (OECTs) combine the principles of electrochemistry and organic electronics. Here, the current flow is governed by the coordinated movement of ions and electrons. Typically, ions from an electrolyte enter an organic channel and modify its doping state, which results in changed conductivity and overall electrical response. OECTs can operate efficiently at low voltages in aqueous environments. It exhibits improved dielectric properties and can integrate naturally well with biological systems. This enables them to be well-suited candidates for real-time biosensing, electrophysiological recording, and in vivo monitoring. Apart from this, their simple fabrication process and robustness on wet or flexible substrates further enhance their compatibility with biological applications. Thus, they offer superior performance compared to organic field-effect transistors (OFETs), which basically operate on interfacial charge modulation. OECTs can also amplify weak biological signals and track environmental parameters. It makes them a versatile tool for point-of-care (POC) diagnostics, wearable health monitoring, pollutant detection, and precision agriculture. However, there are concerns regarding stability, scalability, and environmental impact that may hinder the widespread adoption of OECTs. This review reports the use of green electrochemistry in OECT design, with particular emphasis on environmentally friendly materials, biodegradable polymers, non-toxic electrolytes, low energy manufacturing techniques, and translation opportunities, etc., which is consistent with the vision of a circular economy and reduced e-waste.</p>