The detection of volatile organic compounds (VOCs), such as acetone is critical in clinical diagnostics and environmental monitoring. Acetone is a key biomarker for several medical conditions, most notably diabetes, and is widely used as an industrial solvent. It is present in many household products, leading to environmental exposure. In this study, we introduce a fully printed electrochemical gas sensor fabricated using screen printing technology on a flexible polyethylene terephthalate substrate, employing poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as the conductive polymer and potassium chloride (KCl) as the supporting electrolyte. This configuration leverages the high conductivity and environmental stability of PEDOT:PSS enhanced by the ionic conductivity of KCl to achieve a sensitivity of 0.94 ppm within a linear detection range from 0 to 26 ppm for acetone vapor. The screen-printing technique provides a reproducible and scalable method for sensor fabrication, offering a practical solution for deploying low-cost, flexible, and portable devices. The resulting sensor demonstrates excellent potential for integration into wearable devices for real-time health monitoring and portable units for field testing, providing a significant advancement in the application of flexible electronics to VOC detection. In addition, additive manufacturing allows for consistent layering and scalable production with low waste generation in gas sensor production.