A highly luminescent Zn4L6 tetrahedron is reported with 3.8 nm perylene bisimide edges and hexadentate ZnII–imine chelate vertices. Replacing FeII and monoamines commonly utilized in subcomponent self‐assembly with ZnII and tris(2‐aminoethyl)amine provides access to a metallosupramolecular host with the rare combination of structural integrity at concentrations <10−7 mol L−1 and an exceptionally high fluorescence quantum yield of Φem=0.67. Encapsulation of multiple perylene or coronene guest molecules is accompanied by strong luminescence quenching. We anticipate this self‐assembly strategy may be generalized to improve access to brightly fluorescent coordination cages tailored for host–guest light‐harvesting, photocatalysis, and sensing. FeII‐free and fluorescent: A highly luminescent (Φem=0.67) Zn4L6 tetrahedron with perylene bisimide edges and hexadentate zinc–imine chelate vertices is accessed by dynamic imine–metal coordination self‐assembly. Encapsulation of multiple perylene or coronene guest molecules is detected by quenching of the host emission. The chelate may be generalized to other dyes, improving access to brightly luminescent metallosupramolecular cages.