The colorimetric detection of metal ions has witnessed a surge in advancements, with nanostructured fibers emerging as a powerful platform for environmental monitoring and remediation applications. These fibers offer several advantages, including a high surface area, enhanced sensitivity and selectivity, non-intrusive analysis, rapid response times, robustness under harsh conditions, and user-friendly handling. This unique combination makes them particularly suitable for visible eye detection of metal ions in remote or challenging environments. This review provides a concise overview of recent developments in nanostructured fibers, and their cutting-edge fabrication methods, for the colorimetric-based detection of various heavy metal ions in real-time samples. By exploiting the unique properties of these fibers, colorimetric detection offers a promising and cost-effective approach for heavy metal ion determination. This review delves into the design principles, functionalization strategies, and detection mechanisms employed in these innovative sensors. We highlight the potential of nanostructured fibers as a well-established and efficient platform for the colorimetric detection of heavy metals, paving the way for more sustainable and accessible environmental monitoring solutions.