AbstractThis review is dedicated to electronics materials enabling thin‐film‐based neural interface and bioelectronics devices. First‐generation bioelectronic medicine devices feature hand‐crafted bulk interface electrodes, wires and interconnects, and insulators. This review discusses how modern materials science, especially know‐how repurposed from semiconductor and microdevice technologies, enables next‐generation bioelectronics. Those are divided into two subgroups: second and third generation. The former refers to rigid microscaled devices, while the latter is defined as soft, ultrathin, and flexible microdevices. A critical assessment of different biointerface electrodes, conductors for interconnects, and insulators for substrates, passivation, and encapsulation layers is made. The goal is not to give an exhaustive account of every use‐example of given materials, but to point out specific aspects that are relevant to making the right choices for materials for a given device or application. Unique advantages of specific materials are highlighted, while also focusing on weaker points and caveats that those materials may have. The goal is to have an up‐to‐date handbook for persons entering the field which also points out tips and tricks as well as challenging problems that researchers can be inspired to confront and overcome.