We investigate the Verdet constant in selected heavy metal oxide glasses with good rheological properties for multiple thermal processing. The measurement results prove that lead-bismuth-gallate and tellurite glasses have Verdet constant of 69.33 rad T⁻¹m⁻¹ and 54.91 rad T⁻¹m⁻¹, respectively, at a wavelength of 475 nm. These magneto-optic responses are higher than in the case of pure silica or other commercially available soft glasses used in optical fiber development. The investigated glasses are potential candidates for all-fiber optical current sensors with enhanced sensitivity and resolution.