To date, many methods have been suggested to improve the performance of materials in various applications by applying new physical and chemical properties at the nanometer scale in the form of nanodots, nanowires, and nanofilms. However, most of the proposed methods are difficult to apply to industrial settings due to their size limitations. In that sense, the realization of 3D nanostructured materials is significant for practical use of nanotechnology. The continuous 3D nanostructuring insures the maximum utilization of materials efficiency and improves the stability through well-ordered structures. In this respect, 3D nanostructures of materials can be useful for energy conversion applications such as thermoelectric, piezoelectric, and electrocatalytic applications. Herein, we briefly overview 3D nanofabrication methods to convert the materials in the 3D nanostructures, followed by a review on the advantages of 3D ordered nanoelectrodes for high-performance energy conversion applications.