Leach resistant titanate hollandite-rich ceramic melts incorporating Cs have been prepared in air by melting, in spite of the previously observed high Cs leach rates of (hollandite-bearing) synroc-C melted in air. The absence of Mo in the samples facilitated the incorporation of the Cs into the hollandite phase. Detailed analysis of the samples by electron microscopy is presented on materials rich in Fe- and Mn- substituted titanate hollandites which were fabricated by melting in air. These samples had normalised Cs leachate concentrations of < 0.3 g/1 in the PCT-B test. This paper also reports the solid solubility limits of Cs in single-phase hollandite BaxCs y(M3+)2x+yTi8-2x-yO16 and BaxCsy(M2+)x+y/2Ti 8-x-y/2O16 ceramic formulations where M = Mn or Fe.