We report phase diagrams for amphiphilic block copolymers prepared via ring-opening metathesis polymerization (ROMP). A library of 30 block copolymers with variable hydrophilic functionality, block ratios, and degrees of polymerization was prepared, and the resulting assemblies were analyzed by small-angle neutron scattering (SANS) and cryo-transmission electron microscopy (cryo-TEM). A phase diagram of the self-assemblies was constructed for each of the various copolymer systems screened, representing the first of its kind for polynorbornene block copolymers in dilute solutions. Furthermore, we take advantage of kinetic control in the preparation of an array of particle morphologies accessed from the same polymer structure.