In nature, the fusion of phospholipid vesicles is regulated and catalyzed by highly specialized SNARE proteins. A key step in this process is to bring about close apposition of the lipid bilayers that are destined to fuse. Inspired by nature's use of molecular recognition between receptor proteins, we developed a method to force bilayers into proximity by the selective hybridization of membrane-anchored DNA strands. We demonstrate that this forced bilayer contact triggers vesicle fusion.