<p>The advent of nanotechnology has transformed bioelectronics, shifting devices from bulky and rigid forms to lightweight, flexible, and tunable materials that can be introduced in complex systems for the improvement of performance. Central to this evolution is the incorporation of two-dimensional (2D) nanomaterials, which often combine flexibility, high conductivity, biocompatibility, and large surface area. These properties allow for better contact with biological tissues such as skin, brain, heart, and other organs, resulting in enhanced signal detection and device integration. Tunable conductivity improves signal speed and clarity, while biocompatibility minimizes adverse reactions in medical applications. Their large surface area also enables the detection of ultralow concentrations of biomarkers, which is crucial for early and accurate diagnosis. These advantages support the development of continuous health monitoring through wearable technologies. Taking upon these aspects of flexible 2D nanomaterials and their derivatives, this article focuses on several materials such as graphene, graphitic carbon nitride (g-C₃N₄), phosphorene (black phosphorus, bP), TMDs, and MXenes, along with their composites. Furthermore, the following sections cover topics such as synthesis methods (top-down and bottom-up), key characterization techniques, and their applications in flexible electronic devices, wearable sensors, energy harvesting and storage, and optoelectronic devices. The article concludes by addressing current challenges and discussing future research directions in this rapidly advancing field.</p> Graphical abstract <p></p>