Conductive hydrogels (CHs) are promising materials for wearable devices due to their softness, flexibility, and high conductivity. They are suitable for applications in skin-contact electronics and biomedical devices because of their biocompatibility and conformality. This review summarizes recent progress in the preparation and fabrication of CHs for smart wearable devices, discussing improvements in mechanical, electrical, and functional properties. It also reviews recent examples of innovative and highly functional devices based on CHs that can be seamlessly integrated into daily life. CHs are a special class of hydrogels that can conduct electricity due to the presence of intrinsically conductive materials, functionalized conductive polymers, or conducting ions in insulating polymers. They are categorized into two types: CP-based and non-CP-based. CP-based CHs are prepared using conductive polymers such as polypyrrole (PPy) and polyaniline (PANI), while non-CP-based CHs incorporate conducting fillers like metal-based materials, carbon nanotubes (CNTs), and graphene. These fillers enhance the electrical conductivity of the hydrogels. Various methods are used to fabricate CHs, including in situ polymerization, post-polymerization/coating, and immersion in electrolytes. In situ polymerization involves the simultaneous cross-linking of conjugated monomers in a hydrogel matrix, while post-polymerization involves the immersion of preformed hydrogels in a monomer solution. Immersion in electrolytes enhances the conductivity of non-CP-based CHs by facilitating the transport of electrical charge within the hydrogel network. Gradient structures, characterized by a gradual change in properties or structure along a specified direction, have been developed to enhance specific functionalities. These structures allow for the adjustment of conductive networks and can be achieved through various methods such as soaking strategies and sequential immersion in acidic solutions. The fabrication of CHs with controlled shapes and dimensions is essential for practical applications. Various 3D printing methods, including direct ink writing (DIW), stereolithography (SLA), digital light processing (DLP), inkjet printing, and microfluidic spinning, are used to fabricate CHs with desired shapes. These methods enable the production of complex structures with high resolution and precision. In summary, CHs have shown great potential for use in wearable devices due to their unique properties, including high conductivity, flexibility, and biocompatibility. The development of CHs presents challenges and opportunities that highlight the need for novel fabrication techniques and advanced materials. The integration of CHs into daily life is becoming increasingly feasible with the continuous advancements in material science and device technology.Conductive hydrogels (CHs) are promising materials for wearable devices due to their softness, flexibility, and high conductivity. They are suitable for applications in skin-contact electronics and biomedical devices because of their biocompatibility and conformality. This review summarizes recent progress in the preparation and fabrication of CHs for smart wearable devices, discussing improvements in mechanical, electrical, and functional properties. It also reviews recent examples of innovative and highly functional devices based on CHs that can be seamlessly integrated into daily life. CHs are a special class of hydrogels that can conduct electricity due to the presence of intrinsically conductive materials, functionalized conductive polymers, or conducting ions in insulating polymers. They are categorized into two types: CP-based and non-CP-based. CP-based CHs are prepared using conductive polymers such as polypyrrole (PPy) and polyaniline (PANI), while non-CP-based CHs incorporate conducting fillers like metal-based materials, carbon nanotubes (CNTs), and graphene. These fillers enhance the electrical conductivity of the hydrogels. Various methods are used to fabricate CHs, including in situ polymerization, post-polymerization/coating, and immersion in electrolytes. In situ polymerization involves the simultaneous cross-linking of conjugated monomers in a hydrogel matrix, while post-polymerization involves the immersion of preformed hydrogels in a monomer solution. Immersion in electrolytes enhances the conductivity of non-CP-based CHs by facilitating the transport of electrical charge within the hydrogel network. Gradient structures, characterized by a gradual change in properties or structure along a specified direction, have been developed to enhance specific functionalities. These structures allow for the adjustment of conductive networks and can be achieved through various methods such as soaking strategies and sequential immersion in acidic solutions. The fabrication of CHs with controlled shapes and dimensions is essential for practical applications. Various 3D printing methods, including direct ink writing (DIW), stereolithography (SLA), digital light processing (DLP), inkjet printing, and microfluidic spinning, are used to fabricate CHs with desired shapes. These methods enable the production of complex structures with high resolution and precision. In summary, CHs have shown great potential for use in wearable devices due to their unique properties, including high conductivity, flexibility, and biocompatibility. The development of CHs presents challenges and opportunities that highlight the need for novel fabrication techniques and advanced materials. The integration of CHs into daily life is becoming increasingly feasible with the continuous advancements in material science and device technology.