High sensitivity imposes strict requirements on a sensing platform, for which nanostructured arrays are promising candidates. The template‐assisted method is an effective strategy to prepare various nanostructured arrays, which are widely developed for different sensing applications. Herein, nanostructured array based sensing platforms prepared from four widely used templates, a colloidal monolayer, anodic aluminum oxide, block copolymer, and a nanoimprint mold, are reviewed. In a series of sensing applications (e.g., biosensing and gas sensing), the resulting nanostructure‐array‐based platforms are high sensitive owing to their advanced morphology features: 1) high‐density alignment of arrayed nanostructures, 2) high surface‐to‐volume ratio, and 3) convex‐rich morphology. In surface‐enhanced Raman spectroscopy (SERS) applications, noble‐metal particle arrays with high‐density alignment produce an enhanced SERS signal owing to a strong concentration of plasmonic resonance on the substrate. To sense biomolecules in solution and gaseous molecules, arrays with a high surface‐to‐volume ratio or convex‐rich morphology can sensitively respond to changes in the environment. Moreover, the nanostructure‐array‐based sensing platforms are divided into three types (0D, 1D, and 3D nanostructured arrays) to demonstrate the morphological origin of the sensing performances.