Arsenic poisoning of water supplies is a major worldwide health issue related to exposure to severe diseases, including cancer and neurological disorders. Concerning their complexity, expense, and nature, conventional identification methods could be useless. However, affordable, accurate, and real-time arsenic monitoring substitutes are provided by fresh advances in inventive sensor technology. These sensors improve the sensitivity and selectivity by means of materials including nanomaterials such as graphs, gold nanoparticles, and metal–organic frameworks (MOFs). These sensors have recently shown a rather remarkable capacity to detect arsenic in several water sources. Although electrochemical sensors based on images and gold nanoparticles show remarkable sensitivity and specificity, quartz crystal microbalance sensors provide a cheap and easy approach for monitoring surface water. Linking these sensors to cloud technology and the Internet of Things (IoT) allows real-time data processing and ongoing condition monitoring. This approach allows one to find and respond to arsenic pollution much faster. This is very important and is typically required in rural areas where traditional testing methods often fail. However, many challenges persisted in spite of these technical advances: preserving long-term sensor stability, lowering interference from coexisting contaminants, and managing legal approval processes. Current research is aimed at developing sensors more robust, compact, and energy efficient if it is to be utilized more extensively and regularly. Wearable sensors also let those living in high-risk environments track exposure in real time. We review the present situation of smart sensor technologies for arsenic detection, stressing its potential to greatly improve worldwide water safety monitoring. Emphasizing the importance of ongoing research and development to solve current constraints and increase the implementation of these technologies in practical environments, it also addresses the difficulties and future directions in this subject.