A one‐step method to fabricate a biomimetic dual‐scale hierarchical structure for a transparent anti‐reflective, self‐cleaning layer for organic solar cells is reported. Template‐mediated UV replica molding is used to directly create a multi‐functional surface with an acrylate‐functionalized perfluoropolyether without complicated processing steps. The surface exhibits superhydrophobic properties and self‐cleaning characteristics. In addition, the surface leads to an enhancement of photovoltaic power conversion efficiency by ≈10% as a result of reflection suppression and transmittance enhancement. The method can easily be applied to large area substrates (22 cm × 24 cm) in a cost‐effective manner. Furthermore, the solar cell can withstand harsh outdoor conditions for a long time, without a notable change in the device performance, owing to robust surface layer and non‐fouling properties.