The construction of metallic nanostructures with customizable morphologies and complex shapes has been an essential pursuit in nanoscience. DNA nanotechnology has enabled the fabrication of increasingly complex DNA nanostructures with unprecedented specificity, programmability and subnanometer precision, which makes it an ideal approach to rationally organize metallic nanostructures. Here we report an Assemble, Grow and Lift-Off (AGLO) strategy to construct robust standalone gold nanostructures with pre-designed customizable shapes in solution, using only a simple 2D DNA origami sheet as a versatile transient template. Gold nanoparticle (AuNP) seeds were firstly assembled onto the pre-designed binding sites of the DNA origami template and then additional gold was slowly deposited onto the AuNP seeds. The growing seed surfaces eventually merge with adjacent seeds to generate one continuous gold nanostructure in a pre-designed shape, which can then be lifted off the origami template. Diverse customized patterns of templated AuNP seeds were successfully transformed into corresponding gold nanostructures with the target structure transformation percentage over 80%. Moreover, the AGLO strategy can be incorporated with a magnetic bead separation platform to enable the easy recycling of the excess AuNP seeds and DNA components. Electronic supplementary information (ESI) available: Experimental details, DNA sequences and modications, DNA origami design, seed-origami assembly and gold growth optimizations, additional experimental results, additional AFM and TEM images. See