The growing global demand for water quality monitoring, driven by industrialization and pollution, underscores the need for efficient detection systems. Poly(3,4-ethylenedioxythiophene) (PEDOT)-based electrochemical sensors have emerged as promising tools due to their high conductivity, stability, and biocompatibility. This review highlights recent advancements in PEDOT-based sensors for detecting water pollutants, including heavy metals and organic contaminants. It explores synthesis methods and functionalization techniques that enhance PEDOT's sensitivity and selectivity under diverse conditions, supporting real-time monitoring. Innovations such as combining PEDOT with nanomaterials and the Internet of Things have expanded its capabilities, enabling continuous, accurate assessments. However, challenges remain in improving PEDOT's stability, scalability, and selectivity in real-world environments. This review summarizes the current progress, addresses ongoing challenges, and discusses future directions, such as integrating PEDOT with metal-organic frameworks and composites, to develop reliable, high-performance environmental sensors.