Fog harvesting is recognized as one of the most sustainable means of freshwater collection. Synthetic fog harvesting surfaces have been predominantly inspired from the desert beetle's exoskeleton which exhibits a bumpy topography. This topography underlies an alternating hydrophilic-hydrophobic pattern which has been the basis of several bio-inspired fog harvesting surfaces. However, replication of such hydrophilic-hydrophobic patterns involves multiple processing steps and tedious incorporation of functional/chemical groups at precise locations. On the other hand, surface topography or texture has proven to be insufficient in realizing an efficient fog harvesting surface. This is because micro-or nano-scale textures alone fail to simultaneously maximize the rate of droplet condensation and disposal, which are the two key aspects of efficient fog harvesting. Herein, we report that a hierarchically-textured surface, consisting of micro-lenses arrays covered with high aspect-ratio nanoscale fibrils, can fulfil these two key requirements for maximizing fog harvesting efficiency. While the micro-lenses enable faster droplet condensation, the cluster of nanoscale fibrils impart superhydrophobicity that aids in intermittent droplet disposal. Together, the topography achieves a fog collection efficiency similar to 5-6 times higher than that of the planar counterpart. Moreover, this hierarchical texture is fabricated by a simple one-step nanoimprinting approach which is scalable to arbitrarily large-area flexible substrates.