The 2024 Roadmap on 2D Topological Insulators provides an overview of recent advances and challenges in the field of 2D topological insulators (2DTIs). The roadmap is edited by Bent Weber and Michael S. Fuhrer, and includes contributions from researchers from various institutions around the world. The abstract highlights the unique electronic band structure of 2DTIs, which features 1D spin-momentum locked metallic edge states, both helical and chiral, surrounding an electrically insulating bulk. The field has seen significant progress over the past 40 years, with several materials now available that exhibit sizable bulk energy gaps, promising applications at room temperature. The roadmap covers computational perspectives, material synthesis, physical characterization, and device perspectives, including the potential for combining 2DTIs with other functional materials such as multiferroics, ferromagnets, and superconductors. It also discusses the challenges in material synthesis, disorder control, and device fabrication, as well as the potential for realizing topological phase transitions and non-Abelian quasiparticles in 2DTIs. The roadmap aims to provide a status update on the field, highlighting both the achievements and the remaining challenges in understanding and applying 2DTIs.The 2024 Roadmap on 2D Topological Insulators provides an overview of recent advances and challenges in the field of 2D topological insulators (2DTIs). The roadmap is edited by Bent Weber and Michael S. Fuhrer, and includes contributions from researchers from various institutions around the world. The abstract highlights the unique electronic band structure of 2DTIs, which features 1D spin-momentum locked metallic edge states, both helical and chiral, surrounding an electrically insulating bulk. The field has seen significant progress over the past 40 years, with several materials now available that exhibit sizable bulk energy gaps, promising applications at room temperature. The roadmap covers computational perspectives, material synthesis, physical characterization, and device perspectives, including the potential for combining 2DTIs with other functional materials such as multiferroics, ferromagnets, and superconductors. It also discusses the challenges in material synthesis, disorder control, and device fabrication, as well as the potential for realizing topological phase transitions and non-Abelian quasiparticles in 2DTIs. The roadmap aims to provide a status update on the field, highlighting both the achievements and the remaining challenges in understanding and applying 2DTIs.