Preparation of polyether single-chain nanoparticles (SCNPs) has remained as an elusive issue in spite of the significant interest in the synthesis of polyether derivatives with complex architectures (i.e., star-shaped, cyclic, multicyclic, and supramolecular structures). In this work, we report the facile access to polyether SCNPs by combining zwitterionic ring-opening polymerization (ZROP) and thiol-yne coupling (TYC) techniques. Linear copolymers of tetrahydrofuran (THF) and glycidyl propargyl ether (GPgE), P(GPgE-co-THF), and terpolymers of THF, GPgE, and glycidyl phenyl ether (GPE), P(THF-GPgE-GPE), having naked alkyne functional groups (10-21 mol %) were synthesized through ZROP at high content of THF in the feed. Only P(THF-GPgE-GPE) terpolymers were found to give polyether SCNPs upon photoactivated TYC reaction by working at appropriate dilution conditions (0.5 mg/mL) and using 3,6-dioxa-1,8-octane-dithiol as homobifunctional cross-linker. The different monomer sequence distribution in the copolymers when compared to that in the terpolymers was the responsible for this behavior, as revealed by in situ polymerization C-13 nuclear magnetic resonance measurements. A significant reduction in intrinsic viscosity was observed upon SCNP formation. Analysis of hydrodynamic data from size exclusion chromatography with triple detection in terms of Mark-Houwink-Sakurada plots revealed that the degree of compaction increases upon increasing the alkyne content in the SCNP precursor. Polyether SCNPs were found to be noncrystalline rubbery materials at room temperature.