Nanoscience has witnessed wide developments in various directions, in addition to its crossing through different vital medical and industrial applications. This prompted the development of green nanotechnology that is environmentally friendly with low toxicity, less energy use, and low eco-hazard. So, algae as green autotrophic organisms, gain increasing attention from nanotechnologists, giving a space for the arising of a new field "Algae nanotechnology", where the algae can be used either directly or via mimicry of their unique features and diversity. Algae can biosynthesis nanoparticles in intercellular or extracellular ways, depending on their cellular reactions inside the cells, their secondary metabolites, or extraction of the algal contents. The different ways of using algae for nanoparticles biosynthesis make it available to control the synthesizing of ecofriendly & biocompatible nanoparticles, with different types and morphologies. This review provides an overview of the previous efforts in this emerging field, giving a summary of the ability of algae in nanotechnology, besides future prospective of these trends in algal nanotechnology.