Mercury, as a widespread heavy metal pollutant, poses a serious threat to both human health and the ecosystem. It is of great significance to develop efficient mercury removal technologies for reducing elemental mercury (Hg0) emissions from flue gas and controlling atmospheric mercury pollution. Adsorption has emerged as a simple, practical, and promising method for mercury removal, and various types of adsorbents have been developed for the efficient capture and recovery of Hg0 from flue gas. In this work, we systematically classified adsorbents based on their effective components and provided an in-depth examination of their characteristics, preparation methods, Hg0 removal performance, and adsorption mechanisms. Furthermore, we conducted a thorough comparative analysis of these materials from multiple perspectives, examining their performance and characteristics. Adsorbents for mercury removal can broadly be classified into four main categories: carbon-based and modified materials, metal oxides, metal sulfides, and other innovative materials. Carbon-based and modified materials are particularly effective in removing Hg0 due to their large specific surface area and the presence of various functional groups, such as C—O, C—S, C—Cl. However, these adsorbents suffer from limitations such as poor heat resistance and insufficient functional groups. As a result, they exhibit low adsorption capacities, poor stability, and limited recyclability. Metal oxide adsorbents are primarily composed of iron and manganese oxides, forming various crystal structures. These adsorbents are notable for their operational stability across a broad temperature range, from room temperature up to 250 ℃, as well as their large adsorption capacities. Moreover, they benefit from thermal stability and maintain their effectiveness over multiple cycles. Metal sulfide adsorbents primarily rely on the abundant unsaturated S-sites to achieve efficient adsorption of Hg0. Their advantages include high activity, a wide operational temperature range, and large adsorption capacities. However, the high temperatures required for thermal regeneration can easily degrade their activity, posing challenges for recyclability. Based on the above analysis and the current advances in adsorbent research, we illustrate the respective advantages and disadvantages of different types of adsorbents and propose targeted suggestions for their further development. This work provides novel insights and useful references for the development of new materials and their potential applications in mercury removal technologies based on adsorption.