Convenient synthesis of a range of water-soluble polythionylphosphazene polyelectrolytes is reported. Facile reaction of 3-(dimethylamino)propylamines with the substitutionally labile poly(chlorothionylphosphazene) 2, which is generated via thermal ring-opening polymerization of the cyclic thionylphosphazene 1, afforded the water-soluble polymer 5. The cationic polymer 6 was obtained upon quaternization of the dimethylamino groups in polymer 5 in the presence of dimethyl sulfate. The luminescent cationic polymer 7 was prepared through the covalent attachment of 30 mol % loading of an amino-functionalized ruthenium phenanthroline complex in the polythionylphosphazene side chains. The anionic polymeric precursor 14 was synthesized via substitution reactions of poly(chlorothionylphosphazene) 2 with amine 12. Upon removal of the protective silyl groups, the anionic polythionylphosphazene 15 was obtained. All three polyelectrolytes 6, 7, and 15 were readily soluble in water, making them potentially useful materials for a range of applications.