The absence of ideal flexible and transparent electrodes (FTEs) has hindered the realization of printable electronics for future ubiquitous technology. We report the creation of innovative ‘polymer-metal hybrid electrodes’ with unprecedented FTE performances, including a bending radius < 1 mm, a visible-range transmittance > 95% and a sheet resistance < 10 Ω/□. These remarkable features arise from a surface modification of the plastic substrates using an amine-containing nonconjugated polyelectrolyte, which provides ideal metal-nucleation sites with a density on the atomic scale (approximately 4 Å), in combination with the successive deposition of a facile anti-reflective coating using a conducting polymer. The hybrid electrodes are fully functional as universal FTEs for flexible electronic applications, such as organic solar cells that exhibit a high power conversion efficiency of 10% and organic light-emitting diodes that can outperform any transparent conducting oxides.