Building functional mimics of cell membranes is an important task toward the development of synthetic cells. So far, lipid and amphiphilic block copolymers are the most widely used amphiphiles with the bilayers by the former lacking stability while membranes by the latter are typically characterized by very slow dynamics. Herein, a new type of Janus dendrimer containing a zwitterionic phosphocholine hydrophilic headgroup (JDPC) and a 3,5‐substituted dihydrobenzoate‐based hydrophobic dendron is introduced. JDPC self‐assembles in water into zwitterionic dendrimersomes (z‐DSs) that faithfully recapitulate the cell membrane in thickness, flexibility, and fluidity, while being resilient to harsh conditions and displaying faster pore closing dynamics in the event of membrane rupture. This enables the fabrication of hybrid DSs with components of natural membranes, including pore‐forming peptides, structure‐directing lipids, and glycans to create raft‐like domains or onion vesicles. Moreover, z‐DSs can be used to create active synthetic cells with life‐like features that mimic vesicle fusion and motility as well as environmental sensing. Despite their fully synthetic nature, z‐DSs are minimal cell mimics that can integrate and interact with living matter with the programmability to imitate life‐like features and beyond. The synthesis of a phosphocholine‐based Janus dendrimer is reported, which lacks the “weak points” that result in the chemical and physical instability of natural liposomes. Despite their synthetic nature, the resulting self‐assembled dendrimersomes recapitulate the most important physical properties of cell membranes. This enables functionalization with natural functional molecules as well as mimicry of cellular functions on a basic level.