Severe disease and environmental pollution derived from heavy metal ions has become one of the major problems in global public health. In particular, mercury(II) as one type of highly poisonous pollutant can destroy human metabolism, central nervous system, and immune system, representing a critical threat to living systems. Therefore, exploitation of new strategies for designing and synthesizing eco‐friendly, efficient, and economical materials for selective detection and removal of Hg2+ is of great importance. Among the various measures for sensing, detection, and removal of mercury ions, advanced functional systems including nanomaterials, polymers, aggregation‐induced emission luminogens, and porous materials have attracted considerable attention over the past years due to their capabilities of real‐time detection, rapid removal, great anti‐interference, quick response, high selectivity, and low limit of detection. In this review, some efficient techniques and strategies for the detection and removal of mercury in aqueous solutions using the abovementioned functional materials are overviewed and the ways in which these advanced material systems are used to tackle the problem of mercury pollution are also discussed. The recent advanced systems of mercury(II) ion detection and removal based on nanomaterials, polymers, AIEgens, and porous materials are summarized according to their quick response, high sensitivity, outstanding selectivity, and favorable removal efficiency as sensing platforms. Meanwhile, the development prospects, opportunities, and challenges in the field are also discussed.